Method for transmitting and receiving plurality of physical downlink shared channels in wireless communication system, and device for same

ABSTRACT

The present specification provides a method for transmitting and receiving a plurality of PDSCHs in a wireless communication system and a device for same. In particular, the method carried out by a terminal may comprise the steps of: receiving configuration information for configuring a number K of time-unit groups for receiving a plurality of PDSCHs via different quasi co-location (QCL) source signals; receiving PDSCH configuration information including information about a plurality of transmission configuration indication (TCI) states; receiving information about a number K of TCI states, corresponding to the number K of time-unit groups, among the plurality of TCI states; and receiving the plurality of PDSCHs on the basis of the number K of TCI states.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system and,more particularly, to a method of transmitting and receiving a pluralityof physical downlink shared channels (PDSCHs) and an apparatussupporting the same.

BACKGROUND ART

A mobile communication system has been developed to provide a voiceservice while ensuring the activity of a user. However, the area of themobile communication system has extended to a data service in additionto a voice. Due to the current explosive increase in traffic, there is ashortage of resources, and thus users demand a higher speed service.Accordingly, there is a need for a more advanced mobile communicationsystem.

Requirements for a next-generation mobile communication system need tobe able to support the accommodation of explosive data traffic, adramatic increase in the data rate per user, the accommodation of asignificant increase in the number of connected devices, very lowend-to-end latency, and high energy efficiency. To this end, varioustechnologies, such as dual connectivity, massive multiple input multipleoutput (MIMO), in-band full duplex, non-orthogonal multiple access(NOMA), super wideband support, and device networking, are researched.

DISCLOSURE Technical Problem

The present disclosure proposes a method of indicating TCI states (orQCL reference signals) to be used in multiple time units when aplurality of PDSCHs is transmitted and received through the multipletransmission points, and an apparatus therefor.

Technical problems to be solved by the disclosure are not limited by theaforementioned technical problems, and those skilled in the art to whichthe disclosure pertains may evidently understand other technicalproblems not mentioned above from the following description.

Technical Solution

The present disclosure proposes a method of transmitting and receiving aplurality of physical downlink shared channels (PDSCHs) in a wirelesscommunication system.

The method performed by a user equipment (UE) may include receivingconfiguration information for configuring K time unit groups to receivethe plurality of PDSCHs through different quasi co-location (QCL) sourcesignals, receiving PDSCH configuration information including informationfor a plurality of transmission configuration indication (TCI) states,receiving information for K TCI states corresponding to the K time unitgroups among the plurality of TCI states, and receiving the plurality ofPDSCHs based on the K TCI states.

Furthermore, in the method of the present disclosure, receiving theinformation for the K TCI states may include receiving a media accesscontrol (MAC) control element (CE) including grouping information forthe plurality of TCI states and receiving downlink control information(DCI) indicating a specific group including the K TCI states.

Furthermore, in the method of the present disclosure, the DCI mayschedule a plurality of PDSCHs in time units.

Furthermore, in the method of the present disclosure, the K TCI statesmay be used to receive the PDSCHs in corresponding time unit groups,respectively.

Furthermore, in the method of the present disclosure, the TCI state mayinclude information for a QCL reference signal and information for a QCLtype.

Furthermore, in the method of the present disclosure, an antenna port ofa PDSCH demodulation reference signal of each of the time unit groupsmay be assumed to have a QCL relation with an antenna port of a QCLreference signal mapped to each of the time unit groups.

Furthermore, in the method of the present disclosure, the time unitgroup may include multiple time units, and the time unit may include atleast one of one or more slots and/or one or more symbols.

Furthermore, in the method of the present disclosure, the PDSCH may bereceived from a different transmission point, panel, or beam for eachtime unit group.

Furthermore, a user equipment (UE) receiving a plurality of physicaldownlink shard channels (PDSCHs) in a wireless communication system ofthe present disclosure includes a transceiver for transmitting andreceiving radio signals and a processor functionally coupled to thetransceiver. The processor may be configured to control to receiveconfiguration information for configuring K time unit groups to receivethe plurality of PDSCHs through different quasi co-location (QCL) sourcesignals, receive PDSCH configuration information including informationfor a plurality of transmission configuration indication (TCI) states,receive information for K TCI states corresponding to the K time unitgroups among the plurality of TCI states, and receive the plurality ofPDSCHs based on the K TCI states.

Furthermore, a base station (BS) transmitting a plurality of physicaldownlink shared channels (PDSCHs) in a wireless communication system ofthe present disclosure includes a transceiver for transmitting andreceiving radio signals and a processor functionally coupled to thetransceiver. The processor may be configured to control to transmit, toa user equipment (UE), configuration information for configuring K timeunit groups to transmit the plurality of PDSCHs through different quasico-location (QCL) source signals, transmit, to the UE, PDSCHconfiguration information including information for a plurality oftransmission configuration indication (TCI) states, transmit, to the UE,information for K TCI states corresponding to the K time unit groupsamong the plurality of TCI states, and transmit the plurality of PDSCHsto the UE based on the K TCI states.

Furthermore, in the base station of the present disclosure, theprocessor may be configured to transmit, to the UE, a media accesscontrol (MAC) control element (CE) including grouping information forthe plurality of TCI states and transmit, to the UE, downlink controlinformation (DCI) indicating a specific group including the K TCIstates.

Furthermore, in the base station of the present disclosure, the K TCIstates may be used to receive the PDSCHs in corresponding time unitgroups, respectively.

Furthermore, in the base station of the present disclosure, the TCIstate may include information for a QCL reference signal and informationfor a QCL type.

Furthermore, in the base station of the present disclosure, an antennaport of a PDSCH demodulation reference signal of each of the time unitgroups may be assumed to have a QCL relation with an antenna port of aQCL reference signal mapped to each of the time unit groups

Furthermore, in the base station of the present disclosure, the timeunit group may include multiple time units, and the time unit mayinclude at least one of one or more slots and/or one or more symbols.

Furthermore, in the base station of the present disclosure, the PDSCHsmay be transmitted by different transmission points, panels, or beamsfor each time unit group.

Advantageous Effects

According to the present disclosure, there is an effect in that aplurality of PDSCHs can be transmitted and received through differenttransmission points for each TU group by indicating TCI states (or QCLreference signals) to be used in multiple time units through MAC CEinformation and/or DCI information.

Furthermore, according to the present disclosure, there is an effect inthat communication reliability can be improved by transmitting andreceiving a plurality of PDSCHs through different transmission pointsfor each TU group.

Furthermore, according to the present disclosure, there is an effect inthat the field size of DCI indicating TCI states can be reduced bygrouping TCI states to be used in TU groups through MAC CE information.

Furthermore, according to the present disclosure, there is an effect inthat a communication system having high reliability and low latency canbe implemented.

Effects which may be obtained in the present disclosure are not limitedto the aforementioned effects, and other technical effects not describedabove may be evidently understood by a person having ordinary skill inthe art to which the present disclosure pertains from the followingdescription.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and constitute a part of the detaileddescription, illustrate embodiments of the disclosure and together withthe description serve to explain the principle of the disclosure.

FIG. 1 is a diagram showing an AI device to which a method proposed inthe disclosure may be applied.

FIG. 2 is a diagram showing an AI server to which a method proposed inthe disclosure may be applied.

FIG. 3 is a diagram showing an AI system to which a method proposed inthe disclosure may be applied.

FIG. 4 illustrates an example of an overall structure of an NR system towhich a method proposed in the disclosure may be applied.

FIG. 5 illustrates the relation between an uplink frame and a downlinkframe in a wireless communication system to which a method proposed inthe disclosure may be applied.

FIG. 6 illustrates an example of a frame structure in an NR system.

FIG. 7 illustrates an example of a resource grid supported in a wirelesscommunication system to which a method proposed in the disclosure may beapplied.

FIG. 8 illustrates examples of a resource grid per antenna port andnumerology to which a method proposed in the disclosure may be applied.

FIG. 9 illustrates an example of a self-contained structure to which amethod proposed in the disclosure may be applied.

FIG. 10 is a flowchart illustrating an example of a CSI-relatedprocedure.

FIG. 11 is a concept view illustrating an example of a beam-relatedmeasurement model.

FIG. 12 is a diagram illustrating an example of a DL BMprocedure-related Tx beam.

FIG. 13 is a flowchart illustrating an example of a DL BM procedureusing an SSB.

FIG. 14 is a diagram illustrating an example of a DL BM procedure usinga CSI-RS.

FIG. 15 is a flowchart illustrating an example of a received beamdetermination process of a UE.

FIG. 16 is a flowchart illustrating an example of a method ofdetermining, by a base station, a transmission beam.

FIG. 17 is a diagram illustrating an example of resource allocation intime and frequency domains related to the operation of FIG. 14.

FIG. 18 is a flowchart illustrating an example of a beam failurerecovery procedure.

FIGS. 19 and 20 illustrate examples of cross-cell scheduling.

FIG. 21 illustrates a scheme for grouping and alternately transmitting aplurality of TPs by three symbols.

FIG. 22 illustrates an example in which a TU includes three symbols.

FIG. 23 illustrates an example in which the last symbol of a datachannel is punctured or rate-matched.

FIG. 24 illustrates an example in which the transmission of a controlchannel transmitted in the first symbol of a subframe which isconsecutively and subsequently transmitted is omitted in a TP1 in whichthe corresponding subframe is transmitted.

FIG. 25 is a flowchart for describing an operating method of a UE, whichis proposed in the present disclosure.

FIG. 26 is a flowchart for describing an operating method of a basestation, which is proposed in the present disclosure.

FIG. 27 illustrates a communication system 10 to which the presentdisclosure is applied.

FIG. 28 illustrates a wireless device to which the present disclosuremay be applied.

FIG. 29 illustrates another example of a wireless device to which thepresent disclosure is applied.

FIG. 30 illustrates a handheld device to which the present disclosure isapplied.

MODE FOR INVENTION

Reference will now be made in detail to embodiments of the disclosure,examples of which are illustrated in the accompanying drawings. Adetailed description to be disclosed below together with theaccompanying drawing is to describe exemplary embodiments of the presentdisclosure and not to describe a unique embodiment for carrying out thepresent disclosure. The detailed description below includes details toprovide a complete understanding of the present disclosure. However,those skilled in the art know that the present disclosure can be carriedout without the details.

In some cases, in order to prevent a concept of the present disclosurefrom being ambiguous, known structures and devices may be omitted orillustrated in a block diagram format based on core functions of eachstructure and device.

In the present disclosure, a base station (BS) means a terminal node ofa network directly performing communication with a terminal. In thepresent disclosure, specific operations described to be performed by thebase station may be performed by an upper node of the base station, ifnecessary or desired. That is, it is obvious that in the networkconsisting of multiple network nodes including the base station, variousoperations performed for communication with the terminal can beperformed by the base station or network nodes other than the basestation. The “base station (BS)” may be replaced with terms such as afixed station, Node B, evolved-NodeB (eNB), a base transceiver system(BTS), an access point (AP), gNB (general NB), and the like. Further, a“terminal” may be fixed or movable and may be replaced with terms suchas user equipment (UE), a mobile station (MS), a user terminal (UT), amobile subscriber station (MSS), a subscriber station (SS), an advancedmobile station (AMS), a wireless terminal (WT), a machine-typecommunication (MTC) device, a machine-to-machine (M2M) device, adevice-to-device (D2D) device, and the like.

In the following, downlink (DL) means communication from the basestation to the terminal, and uplink (UL) means communication from theterminal to the base station. In the downlink, a transmitter may be apart of the base station, and a receiver may be a part of the terminal.In the uplink, the transmitter may be a part of the terminal, and thereceiver may be a part of the base station.

Specific terms used in the following description are provided to helpthe understanding of the present disclosure, and may be changed to otherforms within the scope without departing from the technical spirit ofthe present disclosure.

The following technology may be used in various wireless access systems,such as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA), single carrier-FDMA(SC-FDMA), non-orthogonal multiple access (NOMA), and the like. The CDMAmay be implemented by radio technology such as universal terrestrialradio access (UTRA) or CDMA2000. The TDMA may be implemented by radiotechnology such as global system for mobile communications (GSM)/generalpacket radio service (GPRS)/enhanced data rates for GSM evolution(EDGE). The OFDMA may be implemented as radio technology such as IEEE802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (evolved UTRA),and the like. The UTRA is a part of a universal mobile telecommunicationsystem (UMTS). 3rd generation partnership project (3GPP) long termevolution (LTE), as a part of an evolved UMTS (E-UMTS) using E-UTRA,adopts the OFDMA in the downlink and the SC-FDMA in the uplink. LTE-A(advanced) is the evolution of 3GPP LTE.

Embodiments of the present disclosure may be supported by standarddocuments disclosed in at least one of IEEE 802, 3GPP, and 3GPP2 whichare the wireless access systems. That is, steps or parts in theembodiments of the present disclosure which are not described to clearlyshow the technical spirit of the present disclosure may be supported bythe standard documents. Further, all terms described in this documentmay be described by the standard document.

3GPP LTE/LTE-A/New RAT (NR) is primarily described for cleardescription, but technical features of the present disclosure are notlimited thereto.

Hereinafter, examples of 5G use scenarios to which a method proposed inthe disclosure may be applied are described.

Three major requirement areas of 5G include (1) an enhanced mobilebroadband (eMBB) area, (2) a massive machine type communication (mMTC)area and (3) an ultra-reliable and low latency communications (URLLC)area.

Some use cases may require multiple areas for optimization, and otheruse case may be focused on only one key performance indicator (KPI). 5Gsupport such various use cases in a flexible and reliable manner.

eMBB is far above basic mobile Internet access and covers media andentertainment applications in abundant bidirectional tasks, cloud oraugmented reality. Data is one of key motive powers of 5G, and dedicatedvoice services may not be first seen in the 5G era. In 5G, it isexpected that voice will be processed as an application program using adata connection simply provided by a communication system. Major causesfor an increased traffic volume include an increase in the content sizeand an increase in the number of applications that require a high datatransfer rate. Streaming service (audio and video), dialogue type videoand mobile Internet connections will be used more widely as more devicesare connected to the Internet. Such many application programs requireconnectivity always turned on in order to push real-time information andnotification to a user. A cloud storage and application suddenlyincreases in the mobile communication platform, and this may be appliedto both business and entertainment. Furthermore, cloud storage is aspecial use case that tows the growth of an uplink data transfer rate.5G is also used for remote business of cloud. When a tactile interfaceis used, further lower end-to-end latency is required to maintainexcellent user experiences. Entertainment, for example, cloud game andvideo streaming are other key elements which increase a need for themobile broadband ability. Entertainment is essential in the smartphoneand tablet anywhere including high mobility environments, such as atrain, a vehicle and an airplane. Another use case is augmented realityand information search for entertainment. In this case, augmentedreality requires very low latency and an instant amount of data.

Furthermore, one of the most expected 5G use case relates to a functioncapable of smoothly connecting embedded sensors in all fields, that is,mMTC. Until 2020, it is expected that potential IoT devices will reach20.4 billion. The industry IoT is one of areas in which 5G performsmajor roles enabling smart city, asset tracking, smart utility,agriculture and security infra.

URLLC includes a new service which will change the industry throughremote control of major infra and a link having ultra reliability/lowavailable latency, such as a self-driving vehicle. A level ofreliability and latency is essential for smart grid control, industryautomation, robot engineering, drone control and adjustment.

Multiple use cases are described more specifically.

5G may supplement fiber-to-the-home (FTTH) and cable-based broadband (orDOCSIS) as means for providing a stream evaluated from gigabits persecond to several hundreds of mega bits per second. Such fast speed isnecessary to deliver TV with resolution of 4K or more (6K, 8K or more)in addition to virtual reality and augmented reality. Virtual reality(VR) and augmented reality (AR) applications include immersive sportsgames. A specific application program may require a special networkconfiguration. For example, in the case of VR game, in order for gamecompanies to minimize latency, a core server may need to be integratedwith the edge network server of a network operator.

Automotive is expected to be an important and new motive power in 5G,along with many use cases for the mobile communication of an automotive.For example, entertainment for a passenger requires a high capacity anda high mobility mobile broadband at the same time. The reason for thisis that future users continue to expect a high-quality connectionregardless of their location and speed. Another use example of theautomotive field is an augmented reality dashboard. The augmentedreality dashboard overlaps and displays information, identifying anobject in the dark and notifying a driver of the distance and movementof the object, over a thing seen by the driver through a front window.In the future, a wireless module enables communication betweenautomotives, information exchange between an automotive and a supportedinfrastructure, and information exchange between automotive and otherconnected devices (e.g., devices accompanied by a pedestrian). A safetysystem guides alternative courses of a behavior so that a driver candrive more safely, thereby reducing a danger of an accident. A next stepwill be a remotely controlled or self-driven vehicle. This requires veryreliable, very fast communication between different self-driven vehiclesand between an automotive and infra. In the future, a self-drivenvehicle may perform all driving activities, and a driver will be focusedon things other than traffic, which cannot be identified by anautomotive itself. Technical requirements of a self-driven vehiclerequire ultra-low latency and ultra-high speed reliability so thattraffic safety is increased up to a level which cannot be achieved by aperson.

A smart city and smart home mentioned as a smart society will beembedded as a high-density radio sensor network. The distributed networkof intelligent sensors will identify the cost of a city or home and acondition for energy-efficient maintenance. A similar configuration maybe performed for each home. All of a temperature sensor, a window andheating controller, a burglar alarm and home appliances are wirelesslyconnected. Many of such sensors are typically a low data transfer rate,low energy and a low cost. However, for example, real-time HD video maybe required for a specific type of device for surveillance.

The consumption and distribution of energy including heat or gas arehighly distributed and thus require automated control of a distributedsensor network. A smart grid collects information, and interconnectssuch sensors using digital information and a communication technology sothat the sensors operate based on the information. The information mayinclude the behaviors of a supplier and consumer, and thus the smartgrid may improve the distribution of fuel, such as electricity, in anefficient, reliable, economical, production-sustainable and automatedmanner. The smart grid may be considered to be another sensor networkhaving small latency.

A health part owns many application programs which reap t he benefits ofmobile communication. A communication system can support remotetreatment providing clinical treatment at a distant place. This helps toreduce a barrier for the distance and can improve access to medicalservices which are not continuously used at remote farming areas.Furthermore, this is used to save life in important treatment and anemergency condition. A radio sensor network based on mobilecommunication can provide remote monitoring and sensors for parameters,such as the heart rate and blood pressure.

Radio and mobile communication becomes increasingly important in theindustry application field. Wiring requires a high installation andmaintenance cost. Accordingly, the possibility that a cable will bereplaced with reconfigurable radio links is an attractive opportunity inmany industrial fields. However, to achieve the possibility requiresthat a radio connection operates with latency, reliability and capacitysimilar to those of the cable and that management is simplified. Lowlatency and a low error probability is a new requirement for aconnection to 5G.

Logistics and freight tracking is an important use case for mobilecommunication, which enables the tracking inventory and packagesanywhere using a location-based information system. The logistics andfreight tracking use case typically requires a low data speed, but awide area and reliable location information.

Artificial Intelligence (AI)

Artificial intelligence means the field in which artificial intelligenceor methodology capable of producing artificial intelligence isresearched. Machine learning means the field in which various problemshandled in the artificial intelligence field are defined and methodologyfor solving the problems are researched. Machine learning is alsodefined as an algorithm for improving performance of a task throughcontinuous experiences for the task.

An artificial neural network (ANN) is a model used in machine learning,and is configured with artificial neurons (nodes) forming a networkthrough a combination of synapses, and may mean the entire model havinga problem-solving ability. The artificial neural network may be definedby a connection pattern between the neurons of different layers, alearning process of updating a model parameter, and an activationfunction for generating an output value.

The artificial neural network may include an input layer, an outputlayer, and optionally one or more hidden layers. Each layer includes oneor more neurons. The artificial neural network may include a synapseconnecting neurons. In the artificial neural network, each neuron mayoutput a function value of an activation function for input signals,weight, and a bias input through a synapse.

A model parameter means a parameter determined through learning, andincludes the weight of a synapse connection and the bias of a neuron.Furthermore, a hyper parameter means a parameter that needs to beconfigured prior to learning in the machine learning algorithm, andincludes a learning rate, the number of times of repetitions, amini-deployment size, and an initialization function.

An object of learning of the artificial neural network may be consideredto determine a model parameter that minimizes a loss function. The lossfunction may be used as an index for determining an optimal modelparameter in the learning process of an artificial neural network.

Machine learning may be classified into supervised learning,unsupervised learning, and reinforcement learning based on a learningmethod.

Supervised learning means a method of training an artificial neuralnetwork in the state in which a label for learning data has been given.The label may mean an answer (or a result value) that must be deduced byan artificial neural network when learning data is input to theartificial neural network. Unsupervised learning may mean a method oftraining an artificial neural network in the state in which a label forlearning data has not been given. Reinforcement learning may mean alearning method in which an agent defined within an environment istrained to select a behavior or behavior sequence that maximizesaccumulated compensation in each state.

Machine learning implemented as a deep neural network (DNN) including aplurality of hidden layers, among artificial neural networks, is alsocalled deep learning. Deep learning is part of machine learning.Hereinafter, machine learning is used as a meaning including deeplearning.

Robot

A robot may mean a machine that automatically processes a given task oroperates based on an autonomously owned ability. Particularly, a robothaving a function for recognizing an environment and autonomouslydetermining and performing an operation may be called an intelligencetype robot.

A robot may be classified for industry, medical treatment, home, andmilitary based on its use purpose or field.

A robot includes a driving unit including an actuator or motor, and mayperform various physical operations, such as moving a robot joint.Furthermore, a movable robot includes a wheel, a brake, a propeller,etc. in a driving unit, and may run on the ground or fly in the airthrough the driving unit.

Self-Driving (Autonomous-Driving)

Self-driving means a technology for autonomous driving. A self-drivingvehicle means a vehicle that runs without a user manipulation or by auser's minimum manipulation.

For example, self-driving may include all of a technology formaintaining a driving lane, a technology for automatically controllingspeed, such as adaptive cruise control, a technology for automaticdriving along a predetermined path, a technology for automaticallyconfiguring a path when a destination is set and driving.

A vehicle includes all of a vehicle having only an internal combustionengine, a hybrid vehicle including both an internal combustion engineand an electric motor, and an electric vehicle having only an electricmotor, and may include a train, a motorcycle, etc. in addition to thevehicles.

In this case, the self-driving vehicle may be considered to be a robothaving a self-driving function.

Extended Reality (XR)

Extended reality collectively refers to virtual reality (VR), augmentedreality (AR), and mixed reality (MR). The VR technology provides anobject or background of the real world as a CG image only. The ARtechnology provides a virtually produced CG image on an actual thingimage. The MR technology is a computer graphics technology for mixingand combining virtual objects with the real world and providing them.

The MR technology is similar to the AR technology in that it shows areal object and a virtual object. However, in the AR technology, avirtual object is used in a form to supplement a real object. Incontrast, unlike in the AR technology, in the MR technology, a virtualobject and a real object are used as the same character.

The XR technology may be applied to a head-mount display (HMD), ahead-up display (HUD), a mobile phone, a tablet PC, a laptop, a desktop,TV, and a digital signage. A device to which the XR technology has beenapplied may be called an XR device.

FIG. 1 is a diagram showing an AI device 100 to which a method proposedin the disclosure may be applied.

The AI device 100 may be implemented as a fixed device or mobile device,such as TV, a projector, a mobile phone, a smartphone, a desktopcomputer, a notebook, a terminal for digital broadcasting, a personaldigital assistants (PDA), a portable multimedia player (PMP), anavigator, a tablet PC, a wearable device, a set-top box (STB), a DMBreceiver, a radio, a washing machine, a refrigerator, a desktopcomputer, a digital signage, a robot, and a vehicle.

Referring to FIG. 1, the terminal 100 may include a communication unit110, an input unit 120, a learning processor 130, a sensing unit 140, anoutput unit 150, memory 170 and a processor 180.

The communication unit 110 may transmit and receive data to and fromexternal devices, such as other AI devices 100 a to 100 er or an AIserver 200, using wired and wireless communication technologies. Forexample, the communication unit 110 may transmit and receive sensorinformation, a user input, a learning model, and a control signal to andfrom external devices.

In this case, communication technologies used by the communication unit110 include a global system for mobile communication (GSM), codedivision multi access (CDMA), long term evolution (LTE), 5G, a wirelessLAN (WLAN), wireless-fidelity (Wi-Fi), Bluetooth™, radio frequencyidentification (RFID), infrared data association (IrDA), ZigBee, nearfield communication (NFC), etc.

The input unit 120 may obtain various types of data.

In this case, the input unit 120 may include a camera for an imagesignal input, a microphone for receiving an audio signal, a user inputunit for receiving information from a user, etc. In this case, thecamera or the microphone is treated as a sensor, and a signal obtainedfrom the camera or the microphone may be called sensing data or sensorinformation.

The input unit 120 may obtain learning data for model learning and inputdata to be used when an output is obtained using a learning model. Theinput unit 120 may obtain not-processed input data. In this case, theprocessor 180 or the learning processor 130 may extract an input featureby performing pre-processing on the input data.

The learning processor 130 may be trained by a model configured with anartificial neural network using learning data. In this case, the trainedartificial neural network may be called a learning model. The learningmodel is used to deduce a result value of new input data not learningdata. The deduced value may be used as a base for performing a givenoperation.

In this case, the learning processor 130 may perform AI processing alongwith the learning processor 240 of the AI server 200.

In this case, the learning processor 130 may include memory integratedor implemented in the AI device 100. Alternatively, the learningprocessor 130 may be implemented using the memory 170, external memorydirectly coupled to the AI device 100 or memory maintained in anexternal device.

The sensing unit 140 may obtain at least one of internal information ofthe AI device 100, surrounding environment information of the AI device100, or user information using various sensors.

In this case, sensors included in the sensing unit 140 include aproximity sensor, an illumination sensor, an acceleration sensor, amagnetic sensor, a gyro sensor, an inertia sensor, an RGB sensor, an IRsensor, a fingerprint recognition sensor, an ultrasonic sensor, a photosensor, a microphone, LIDAR, and a radar.

The output unit 150 may generate an output related to a visual sense, anauditory sense or a tactile sense.

In this case, the output unit 150 may include a display unit foroutputting visual information, a speaker for outputting auditoryinformation, and a haptic module for outputting tactile information.

The memory 170 may store data supporting various functions of the AIdevice 100. For example, the memory 170 may store input data obtained bythe input unit 120, learning data, a learning model, a learning history,etc.

The processor 180 may determine at least one executable operation of theAI device 100 based on information, determined or generated using a dataanalysis algorithm or a machine learning algorithm. Furthermore, theprocessor 180 may perform the determined operation by controllingelements of the AI device 100.

To this end, the processor 180 may request, search, receive, and use thedata of the learning processor 130 or the memory 170, and may controlelements of the AI device 100 to execute a predicted operation or anoperation determined to be preferred, among the at least one executableoperation.

In this case, if association with an external device is necessary toperform the determined operation, the processor 180 may generate acontrol signal for controlling the corresponding external device andtransmit the generated control signal to the corresponding externaldevice.

The processor 180 may obtain intention information for a user input andtransmit user requirements based on the obtained intention information.

In this case, the processor 180 may obtain the intention information,corresponding to the user input, using at least one of a speech to text(STT) engine for converting a voice input into a text string or anatural language processing (NLP) engine for obtaining intentioninformation of a natural language.

In this case, at least some of at least one of the STT engine or the NLPengine may be configured as an artificial neural network trained basedon a machine learning algorithm. Furthermore, at least one of the STTengine or the NLP engine may have been trained by the learning processor130, may have been trained by the learning processor 240 of the AIserver 200 or may have been trained by distributed processing thereof.

The processor 180 may collect history information including theoperation contents of the AI device 100 or the feedback of a user for anoperation, may store the history information in the memory 170 or thelearning processor 130, or may transmit the history information to anexternal device, such as the AI server 200. The collected historyinformation may be used to update a learning model.

The processor 18 may control at least some of the elements of the AIdevice 100 in order to execute an application program stored in thememory 170. Moreover, the processor 180 may combine and drive two ormore of the elements included in the AI device 100 in order to executethe application program.

FIG. 2 is a diagram showing the AI server 200 to which a method proposedin the disclosure may be applied.

Referring to FIG. 2, the AI server 200 may mean a device which istrained by an artificial neural network using a machine learningalgorithm or which uses a trained artificial neural network. In thiscase, the AI server 200 is configured with a plurality of servers andmay perform distributed processing and may be defined as a 5G network.In this case, the AI server 200 may be included as a partialconfiguration of the AI device 100, and may perform at least some of AIprocessing.

The AI server 200 may include a communication unit 210, memory 230, alearning processor 240 and a processor 260.

The communication unit 210 may transmit and receive data to and from anexternal device, such as the AI device 100.

The memory 230 may include a model storage unit 231. The model storageunit 231 may store a model (or artificial neural network 231 a) which isbeing trained or has been trained through the learning processor 240.

The learning processor 240 may train the artificial neural network 231 ausing learning data. The learning model may be used in the state inwhich it has been mounted on the AI server 200 of the artificial neuralnetwork or may be mounted on an external device, such as the AI device100, and used.

The learning model may be implemented as hardware, software or acombination of hardware and software. If some of or the entire learningmodel is implemented as software, one or more instructions configuringthe learning model may be stored in the memory 230.

The processor 260 may deduce a result value of new input data using thelearning model, and may generate a response or control command based onthe deduced result value.

FIG. 3 is a diagram showing an AI system 1 to which a method proposed inthe disclosure may be applied.

Referring to FIG. 3, the AI system 1 is connected to at least one of theAI server 200, a robot 100 a, a self-driving vehicle 100 b, an XR device100 c, a smartphone 100 d or home appliances 100 e over a cloud network10. In this case, the robot 100 a, the self-driving vehicle 100 b, theXR device 100 c, the smartphone 100 d or the home appliances 100 e towhich the AI technology has been applied may be called AI devices 100 ato 100 e.

The cloud network 10 may configure part of cloud computing infra or maymean a network present within cloud computing infra. In this case, thecloud network 10 may be configured using the 3G network, the 4G or longterm evolution (LTE) network or the 5G network.

That is, the devices 100 a to 100 e (200) configuring the AI system 1may be interconnected over the cloud network 10. Particularly, thedevices 100 a to 100 e and 200 may communicate with each other through abase station, but may directly communicate with each other without theintervention of a base station.

The AI server 200 may include a server for performing AI processing anda server for performing calculation on big data.

The AI server 200 is connected to at least one of the robot 100 a, theself-driving vehicle 100 b, the XR device 100 c, the smartphone 100 d orthe home appliances 100 e, that is, AI devices configuring the AI system1, over the cloud network 10, and may help at least some of the AIprocessing of the connected AI devices 100 a to 100 e.

In this case, the AI server 200 may train an artificial neural networkbased on a machine learning algorithm in place of the AI devices 100 ato 100 e, may directly store a learning model or may transmit thelearning model to the AI devices 100 a to 100 e.

In this case, the AI server 200 may receive input data from the AIdevices 100 a to 100 e, may deduce a result value of the received inputdata using the learning model, may generate a response or controlcommand based on the deduced result value, and may transmit the responseor control command to the AI devices 100 a to 100 e.

Alternatively, the AI devices 100 a to 100 e may directly deduce aresult value of input data using a learning model, and may generate aresponse or control command based on the deduced result value.

Hereinafter, various embodiments of the AI devices 100 a to 100 e towhich the above-described technology is applied are described. In thiscase, the AI devices 100 a to 100 e shown in FIG. 3 may be considered tobe detailed embodiments of the AI device 100 shown in FIG. 1.

AI+Robot

An AI technology is applied to the robot 100 a, and the robot 100 a maybe implemented as a guidance robot, a transport robot, a cleaning robot,a wearable robot, an entertainment robot, a pet robot, an unmannedflight robot, etc.

The robot 100 a may include a robot control module for controlling anoperation. The robot control module may mean a software module or a chipin which a software module has been implemented using hardware.

The robot 100 a may obtain state information of the robot 100 a, maydetect (recognize) a surrounding environment and object, may generatemap data, may determine a moving path and a running plan, may determinea response to a user interaction, or may determine an operation usingsensor information obtained from various types of sensors.

In this case, the robot 100 a may use sensor information obtained by atleast one sensor among LIDAR, a radar, and a camera in order todetermine the moving path and running plan.

The robot 100 a may perform the above operations using a learning modelconfigured with at least one artificial neural network. For example, therobot 100 a may recognize a surrounding environment and object using alearning model, and may determine an operation using recognizedsurrounding environment information or object information. In this case,the learning model may have been directly trained in the robot 100 a ormay have been trained in an external device, such as the AI server 200.

In this case, the robot 100 a may directly generate results using thelearning model and perform an operation, but may perform an operation bytransmitting sensor information to an external device, such as the AIserver 200, and receiving results generated in response thereto.

The robot 100 a may determine a moving path and running plan using atleast one of map data, object information detected from sensorinformation, or object information obtained from an external device. Therobot 100 a may run along the determined moving path and running plan bycontrolling the driving unit.

The map data may include object identification information for variousobjects disposed in the space in which the robot 100 a moves. Forexample, the map data may include object identification information forfixed objects, such as a wall and a door, and movable objects, such as aflowport and a desk. Furthermore, the object identification informationmay include a name, a type, a distance, a location, etc.

Furthermore, the robot 100 a may perform an operation or run bycontrolling the driving unit based on a user's control/interaction. Inthis case, the robot 100 a may obtain intention information of aninteraction according to a user's behavior or voice speaking, maydetermine a response based on the obtained intention information, andmay perform an operation.

AI+Self-Driving

An AI technology is applied to the self-driving vehicle 100 b, and theself-driving vehicle 100 b may be implemented as a movable type robot, avehicle, an unmanned flight body, etc.

The self-driving vehicle 100 b may include a self-driving control modulefor controlling a self-driving function. The self-driving control modulemay mean a software module or a chip in which a software module has beenimplemented using hardware. The self-driving control module may beincluded in the self-driving vehicle 100 b as an element of theself-driving vehicle 100 b, but may be configured as separate hardwareoutside the self-driving vehicle 100 b and connected to the self-drivingvehicle 100 b.

The self-driving vehicle 100 b may obtain state information of theself-driving vehicle 100 b, may detect (recognize) a surroundingenvironment and object, may generate map data, may determine a movingpath and running plan, or may determine an operation using sensorinformation obtained from various types of sensors.

In this case, in order to determine the moving path and running plan,like the robot 100 a, the self-driving vehicle 100 b may use sensorinformation obtained from at least one sensor among LIDAR, a radar and acamera.

Particularly, the self-driving vehicle 100 b may recognize anenvironment or object in an area whose view is blocked or an area of agiven distance or more by receiving sensor information for theenvironment or object from external devices, or may directly receiverecognized information for the environment or object from externaldevices.

The self-driving vehicle 100 b may perform the above operations using alearning model configured with at least one artificial neural network.For example, the self-driving vehicle 100 b may recognize a surroundingenvironment and object using a learning model, and may determine theflow of running using recognized surrounding environment information orobject information. In this case, the learning model may have beendirectly trained in the self-driving vehicle 100 b or may have beentrained in an external device, such as the AI server 200.

In this case, the self-driving vehicle 100 b may directly generateresults using the learning model and perform an operation, but mayperform an operation by transmitting sensor information to an externaldevice, such as the AI server 200, and receiving results generated inresponse thereto.

The self-driving vehicle 100 b may determine a moving path and runningplan using at least one of map data, object information detected fromsensor information or object information obtained from an externaldevice. The self-driving vehicle 100 b may run based on the determinedmoving path and running plan by controlling the driving unit.

The map data may include object identification information for variousobjects disposed in the space (e.g., road) in which the self-drivingvehicle 100 b runs. For example, the map data may include objectidentification information for fixed objects, such as a streetlight, arock, and a building, etc., and movable objects, such as a vehicle and apedestrian. Furthermore, the object identification information mayinclude a name, a type, a distance, a location, etc.

Furthermore, the self-driving vehicle 100 b may perform an operation ormay run by controlling the driving unit based on a user'scontrol/interaction. In this case, the self-driving vehicle 100 b mayobtain intention information of an interaction according to auser'behavior or voice speaking, may determine a response based on theobtained intention information, and may perform an operation.

AI+XR

An AI technology is applied to the XR device 100 c, and the XR device100 c may be implemented as a head-mount display, a head-up displayprovided in a vehicle, television, a mobile phone, a smartphone, acomputer, a wearable device, home appliances, a digital signage, avehicle, a fixed type robot or a movable type robot.

The XR device 100 c may generate location data and attributes data forthree-dimensional points by analyzing three-dimensional point cloud dataor image data obtained through various sensors or from an externaldevice, may obtain information for a surrounding space or real objectbased on the generated location data and attributes data, and may outputan XR object by rendering the XR object. For example, the XR device 100c may output an XR object, including additional information for arecognized object, by making the XR object correspond to thecorresponding recognized object.

The XR device 100 c may perform the above operations using a learningmodel configured with at least one artificial neural network. Forexample, the XR device 100 c may recognize a real object inthree-dimensional point cloud data or image data using a learning model,and may provide information corresponding to the recognized real object.In this case, the learning model may have been directly trained in theXR device 100 c or may have been trained in an external device, such asthe AI server 200.

In this case, the XR device 100 c may directly generate results using alearning model and perform an operation, but may perform an operation bytransmitting sensor information to an external device, such as the AIserver 200, and receiving results generated in response thereto.

AI+Robot+Self-Driving

An AI technology and a self-driving technology are applied to the robot100 a, and the robot 100 a may be implemented as a guidance robot, atransport robot, a cleaning robot, a wearable robot, an entertainmentrobot, a pet robot, an unmanned flight robot, etc.

The robot 100 a to which the AI technology and the self-drivingtechnology have been applied may mean a robot itself having aself-driving function or may mean the robot 100 a interacting with theself-driving vehicle 100 b.

The robot 100 a having the self-driving function may collectively referto devices that autonomously run along a given flow without control of auser or that autonomously determine a flow and move.

The robot 100 a and the self-driving vehicle 100 b having theself-driving function may use a common sensing method in order todetermine one or more of a moving path or a running plan. For example,the robot 100 a and the self-driving vehicle 100 b having theself-driving function may determine one or more of a moving path or arunning plan using information sensed through a LIDAR, a radar, acamera, etc.

The robot 100 a interacting with the self-driving vehicle 100 b ispresent separately from the self-driving vehicle 100 b, and may performan operation associated with a self-driving function inside or outsidethe self-driving vehicle 100 b or associated with a user got in theself-driving vehicle 100 b.

In this case, the robot 100 a interacting with the self-driving vehicle100 b may control or assist the self-driving function of theself-driving vehicle 100 b by obtaining sensor information in place ofthe self-driving vehicle 100 b and providing the sensor information tothe self-driving vehicle 100 b, or by obtaining sensor information,generating surrounding environment information or object information,and providing the surrounding environment information or objectinformation to the self-driving vehicle 100 b.

Alternatively, the robot 100 a interacting with the self-driving vehicle100 b may control the function of the self-driving vehicle 100 b bymonitoring a user got in the self-driving vehicle 100 b or through aninteraction with a user. For example, if a driver is determined to be adrowsiness state, the robot 100 a may activate the self-driving functionof the self-driving vehicle 100 b or assist control of the driving unitof the self-driving vehicle 100 b. In this case, the function of theself-driving vehicle 100 b controlled by the robot 100 a may include afunction provided by a navigation system or audio system provided withinthe self-driving vehicle 100 b, in addition to a self-driving functionsimply.

Alternatively, the robot 100 a interacting with the self-driving vehicle100 b may provide information to the self-driving vehicle 100 b or mayassist a function outside the self-driving vehicle 100 b. For example,the robot 100 a may provide the self-driving vehicle 100 b with trafficinformation, including signal information, as in a smart traffic light,and may automatically connect an electric charger to a filling inletthrough an interaction with the self-driving vehicle 100 b as in theautomatic electric charger of an electric vehicle.

AI+Robot+XR

An AI technology and an XR technology are applied to the robot 100 a,and the robot 100 a may be implemented as a guidance robot, a transportrobot, a cleaning robot, a wearable robot, an entertainment robot, a petrobot, an unmanned flight robot, a drone, etc.

The robot 100 a to which the XR technology has been applied may mean arobot, that is, a target of control/interaction within an XR image. Inthis case, the robot 100 a is different from the XR device 100 c, andthey may operate in conjunction with each other.

When the robot 100 a, that is, a target of control/interaction within anXR image, obtains sensor information from sensors including a camera,the robot 100 a or the XR device 100 c may generate an XR image based onthe sensor information, and the XR device 100 c may output the generatedXR image. Furthermore, the robot 100 a may operate based on a controlsignal received through the XR device 100 c or a user's interaction.

For example, a user may identify a corresponding XR image at timing ofthe robot 100 a, remotely operating in conjunction through an externaldevice, such as the XR device 100 c, may adjust the self-driving path ofthe robot 100 a through an interaction, may control an operation ordriving, or may identify information of a surrounding object.

AI+Self-Driving+XR

An AI technology and an XR technology are applied to the self-drivingvehicle 100 b, and the self-driving vehicle 100 b may be implemented asa movable type robot, a vehicle, an unmanned flight body, etc.

The self-driving vehicle 100 b to which the XR technology has beenapplied may mean a self-driving vehicle equipped with means forproviding an XR image or a self-driving vehicle, that is, a target ofcontrol/interaction within an XR image. Particularly, the self-drivingvehicle 100 b, that is, a target of control/interaction within an XRimage, is different from the XR device 100 c, and they may operate inconjunction with each other.

The self-driving vehicle 100 b equipped with the means for providing anXR image may obtain sensor information from sensors including a camera,and may output an XR image generated based on the obtained sensorinformation. For example, the self-driving vehicle 100 b includes anHUD, and may provide a passenger with an XR object corresponding to areal object or an object within a screen by outputting an XR image.

In this case, when the XR object is output to the HUD, at least some ofthe XR object may be output with it overlapping a real object towardwhich a passenger's view is directed. In contrast, when the XR object isdisplayed on a display included within the self-driving vehicle 100 b,at least some of the XR object may be output so that it overlaps anobject within a screen. For example, the self-driving vehicle 100 b mayoutput XR objects corresponding to objects, such as a carriageway,another vehicle, a traffic light, a signpost, a two-wheeled vehicle, apedestrian, and a building.

When the self-driving vehicle 100 b, that is, a target ofcontrol/interaction within an XR image, obtains sensor information fromsensors including a camera, the self-driving vehicle 100 b or the XRdevice 100 c may generate an XR image based on the sensor information.The XR device 100 c may output the generated XR image. Furthermore, theself-driving vehicle 100 b may operate based on a control signalreceived through an external device, such as the XR device 100 c, or auser's interaction.

As smartphones and Internet of Things (ioT) terminals are rapidlyspread, the amount of information exchanged through a communicationnetwork is increasing. As a result, next-generation wireless accesstechnologies can provide faster service to more users than traditionalcommunication systems (or traditional radio access technologies) (e.g.,enhanced mobile broadband communication) Needs to be considered.

To this end, the design of a communication system that considers MachineType Communication (MTC), which provides services by connecting a numberof devices and objects, is being discussed. It is also being discussedas a multiuser of communication systems (e.g., Ultra-Reliable and LowLatency Communication, URLLC) that take into account the reliabilityand/or latency-sensitive services (service) and/or a user equipment.

Hereinafter, in the present disclosure, for convenience of description,the next generation radio access technology is referred to as NR (NewRAT), and the radio communication system to which the NR is applied isreferred to as an NR system.

Definition of Terms

eLTE eNB: The eLTE eNB is the evolution of eNB that supportsconnectivity to EPC and NGC.

gNB: A node which supports the NR as well as connectivity to NGC.

New RAN: A radio access network which supports either NR or E-UTRA orinterfaces with the NGC.

Network slice: A network slice is a network created by the operatorcustomized to provide an optimized solution for a specific marketscenario which demands specific requirements with end-to-end scope.

Network function: A network function is a logical node within a networkinfrastructure that has well-defined external interfaces andwell-defined functional behaviour.

NG-C: A control plane interface used on NG2 reference points between newRAN and NGC.

NG-U: A user plane interface used on NG3 references points between newRAN and NGC.

Non-standalone NR: A deployment configuration where the gNB requires anLTE eNB as an anchor for control plane connectivity to EPC, or requiresan eLTE eNB as an anchor for control plane connectivity to NGC.

Non-standalone E-UTRA: A deployment configuration where the eLTE eNBrequires a gNB as an anchor for control plane connectivity to NGC.

User plane gateway: A termination point of NG-U interface.

Overview of System

FIG. 4 illustrates an example of an overall structure of an NR system towhich a method proposed in the disclosure may be applied.

Referring to FIG. 4, an NG-RAN is configured with an NG-RA user plane(new AS sublayer/PDCP/RLC/MAC/PHY) and gNBs which provide a controlplane (RRC) protocol end for a user equipment (UE).

The gNBs are interconnected through an Xn interface.

The gNBs are also connected to an NGC through an NG interface.

More specifically the gNBs are connected to an access and mobilitymanagement function (AMF) through an N2 interface and to a user planefunction (UPF) through an N3 interface.

NR supports multiple numerologies (or subcarrier spacings (SCS)) forsupporting various 5G services. For example, if SCS is 15 kHz, NRsupports a wide area in typical cellular bands. If SCS is 30 kHz/60 kHz,NR supports a dense urban, lower latency and a wider carrier bandwidth.If SCS is 60 kHz or higher, NR supports a bandwidth greater than 24.25GHz in order to overcome phase noise.

An NR frequency band is defined as a frequency range of two types FR1and FR2. The FR1 and the FR2 may be configured as in Table 1 below.Furthermore, the FR2 may mean a millimeter wave (mmW).

TABLE 1 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing FR1 410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

New Rat (NR) numerology and frame structure

In the NR system, multiple numerologies may be supported. Thenumerologies may be defined by subcarrier spacing and a CP (CyclicPrefix) overhead. Spacing between the plurality of subcarriers may bederived by scaling basic subcarrier spacing into an integer N (or μ). Inaddition, although a very low subcarrier spacing is assumed not to beused at a very high subcarrier frequency, a numerology to be used may beselected independent of a frequency band.

In addition, in the NR system, a variety of frame structures accordingto the multiple numerologies may be supported.

Hereinafter, an orthogonal frequency division multiplexing (OFDM)numerology and a frame structure, which may be considered in the NRsystem, will be described.

A plurality of OFDM numerologies supported in the NR system may bedefined as in Table 2.

TABLE 2 μ Δƒ = 2^(μ) · 15 [kHz] Cyclic prefix 0  15 Normal 1  30 Normal2  60 Normal, Extended 3 120 Normal 4 240 Normal

Regarding a frame structure in the NR system, a size of various fieldsin the time domain is expressed as a multiple of a time unit ofT_(s)=1/(Δf_(max)·N_(f)). In this case, Δf_(max)=480·10³, andN_(f)=4096. DL and UL transmission is configured as a radio frame havinga section of T_(f)=(Δf_(max)N_(f)/100)·T_(s)=10 ms. The radio frame iscomposed of ten subframes each having a section ofT_(sf)=(Δf_(max)N_(f)/1000)·T_(s)=1 ms. In this case, there may be a setof UL frames and a set of DL frames.

FIG. 5 illustrates the relation between an uplink frame and a downlinkframe in a wireless communication system to which a method proposed inthe disclosure may be applied.

As illustrated in FIG. 5, uplink frame number i for transmission from auser equipment (UE) shall start T_(TA)=N_(TA)T_(s) before the start of acorresponding downlink frame at the corresponding UE.

Regarding the numerology μ, slots are numbered in increasing order ofn_(s) ^(μ)∈{0, . . . , N_(subframe) ^(slots,μ)−1} within a subframe andare numbered in increasing order of n_(s,f) ^(μ)∈{0, . . . ,N_(subframe) ^(slots,μ)−1} within a radio frame. One slot consists ofconsecutive OFDM symbols of N_(symb) ^(μ), and N_(symb) ^(μ) isdetermined depending on a numerology used and slot configuration. Thestart of slots n_(s) ^(μ) in a subframe is aligned in time with thestart of OFDM symbols n_(s) ^(μ)N_(symb) ^(μ) in the same subframe.

Not all UEs are able to transmit and receive at the same time, and thismeans that not all OFDM symbols in a downlink slot or an uplink slot areavailable to be used.

Table 3 represents the number N_(symb) ^(slot) of OFDM symbols per slot,the number N_(slot) ^(frame,μ) slot of slots per radio frame, and thenumber N_(slot) ^(subframe,μ) of slots per subframe in a normal CP.Table 4 represents the number of OFDM symbols per slot, the number ofslots per radio frame, and the number of slots per subframe in anextended CP.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14  10  1 1 14  20  2 2 14  40  4 3 14  80  8 4 14 160 16

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

FIG. 6 illustrates an example of a frame structure in an NR system. FIG.6 is merely for convenience of explanation and does not limit the scopeof the disclosure.

In Table 4, in the case of μ=2, i.e., as an example in which asubcarrier spacing (SCS) is 60 kHz, one subframe (or frame) may includefour slots with reference to Table 4, and one subframe={1, 2, 4} slotsshown in FIG. 3, for example, the number of slot(s) that may be includedin one subframe may be defined as in Table 4.

Further, a mini-slot may consist of 2, 4, or 7 symbols, or may consistof more symbols or less symbols.

In relation to physical resources in the NR system, an antenna port, aresource grid, a resource element, a resource block, a carrier part,etc. may be considered.

Hereinafter, the above physical resources that can be considered in theNR system are described in more detail.

First, in relation to an antenna port, the antenna port is defined sothat a channel over which a symbol on an antenna port is conveyed can beinferred from a channel over which another symbol on the same antennaport is conveyed. When large-scale properties of a channel over which asymbol on one antenna port is conveyed can be inferred from a channelover which a symbol on another antenna port is conveyed, the two antennaports may be regarded as being in a quasi co-located or quasico-location (QC/QCL) relation. In this case, the large-scale propertiesmay include at least one of delay spread, Doppler spread, frequencyshift, average received power, and received timing.

FIG. 7 illustrates an example of a resource grid supported in a wirelesscommunication system to which a method proposed in the disclosure may beapplied.

Referring to FIG. 7, a resource grid consists of N_(RB) ^(μ)N_(sc) ^(RB)subcarriers on a frequency domain, each subframe consisting of 14·2μOFDM symbols, but the disclosure is not limited thereto.

In the NR system, a transmitted signal is described by one or moreresource grids, consisting of N_(RB) ^(μ)N_(sc) ^(RB) subcarriers, and2^(μ)N_(symb) ^((μ)) OFDM symbols, where N_(RB) ^(μ)≤N_(RB) ^(max,μ).N_(RB) ^(max,μ) denotes a maximum transmission bandwidth and may changenot only between numerologies but also between uplink and downlink.

In this case, as illustrated in FIG. 8, one resource grid may beconfigured per numerology μ and antenna port p.

FIG. 8 illustrates examples of a resource grid per antenna port andnumerology to which a method proposed in the disclosure may be applied.

Each element of the resource grid for the numerology μ and the antennaport p is called a resource element and is uniquely identified by anindex pair (k, l), where k=0, . . . , N_(RB) ^(μ)N_(sc) ^(RB)−1 is anindex on a frequency domain, and l=0 . . . , 2^(μ)N_(symb) ^((μ))−1refers to a location of a symbol in a subframe. The index pair (k, l) isused to refer to a resource element in a slot, where l=0, . . . ,N_(symb) ^(μ)−1.

The resource element (k,l) for the numerology μ and the antenna port pcorresponds to a complex value a_(k,l l) . When there is no risk forconfusion or when a specific antenna port or numerology is notspecified, the indexes μ and may be dropped, and as a result, thecomplex value may be a_(k,l) ^((p)) or a_(k,l) .

Further, a physical resource block is defined as N_(s) ^(sR)=12consecutive subcarriers in the frequency domain.

Point A serves as a common reference point of a resource block grid andmay be obtained as follows.

-   -   offsetToPointA for PCell downlink represents a frequency offset        between the point A and a lowest subcarrier of a lowest resource        block that overlaps a SS/PBCH block used by the UE for initial        cell selection, and is expressed in units of resource blocks        assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier        spacing for FR2;    -   absoluteFrequencyPointA represents frequency-location of the        point A expressed as in absolute radio-frequency channel number        (ARFCN).

The common resource blocks are numbered from 0 and upwards in thefrequency domain for subcarrier spacing configuration μ.

The center of subcarrier 0 of common resource block 0 for the subcarrierspacing configuration μ coincides with ‘point A’. A common resourceblock number n_(CRB) ^(μ) in the frequency domain and resource elements(k, l) for the subcarrier spacing configuration μ may be given by thefollowing Equation 1.

$\begin{matrix}{n_{CRB}^{\mu} = \left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor} & {〚{{Equation}\mspace{14mu} 1}〛}\end{matrix}$

In this case, k may be defined relative to the point A so that k=0corresponds to a subcarrier centered around the point A. Physicalresource blocks are defined within a bandwidth part (BWP) and arenumbered from 0 to N_(BWP,i) ^(size)−1, where i is No. of the BWP. Arelation between the physical resource block n_(PRB) in BWP i and thecommon resource block n_(CRB) may be given by the following Equation 2.

n _(CRB) =n _(PRB) +N _(BWP,i) ^(start)  [Equation 2]

In this case, N_(BWP,i) ^(start) may be the common resource block wherethe BWP starts relative to the common resource block 0.

Self-Contained Structure

A time division duplexing (TDD) structure considered in the NR system isa structure in which both uplink (UL) and downlink (DL) are processed inone slot (or subframe). The structure is to minimize a latency of datatransmission in a TDD system and may be referred to as a self-containedstructure or a self-contained slot.

FIG. 9 illustrates an example of a self-contained structure to which amethod proposed in the disclosure may be applied. FIG. 9 is merely forconvenience of explanation and does not limit the scope of thedisclosure.

Referring to FIG. 9, as in legacy LTE, it is assumed that onetransmission unit (e.g., slot, subframe) consists of 14 orthogonalfrequency division multiplexing (OFDM) symbols.

In FIG. 9, a region 902 means a downlink control region, and a region904 means an uplink control region. Further, regions (i.e., regionswithout separate indication) other than the region 902 and the region904 may be used for transmission of downlink data or uplink data.

That is, uplink control information and downlink control information maybe transmitted in one self-contained slot. On the other hand, in thecase of data, uplink data or downlink data is transmitted in oneself-contained slot.

When the structure illustrated in FIG. 9 is used, in one self-containedslot, downlink transmission and uplink transmission may sequentiallyproceed, and downlink data transmission and uplink ACK/NACK receptionmay be performed.

As a result, if an error occurs in the data transmission, time requireduntil retransmission of data can be reduced. Hence, the latency relatedto data transfer can be minimized.

In the self-contained slot structure illustrated in FIG. 9, a basestation (e.g., eNodeB, eNB, gNB) and/or a user equipment (UE) (e.g.,terminal) require a time gap for a process for converting a transmissionmode into a reception mode or a process for converting a reception modeinto a transmission mode. In relation to the time gap, if uplinktransmission is performed after downlink transmission in theself-contained slot, some OFDM symbol(s) may be configured as a guardperiod (GP).

Channel state information (CSI) related procedure

In a new radio (NR) system, a channel state information-reference signal(CSI-RS) is used for time/frequency tracking, CSI computation, layer 1(L1)-reference signal received power (RSRP) computation, and mobility.

“A and/or B” used in the present disclosure may be interpreted as thesame meaning as that “A and/or B” includes at least one of A or B.”

The CSI computation is related to CSI acquisition, and the L1-RSRPcomputation is related to beam management (BM).

Channel state information (CSI generally refers to information which mayindicate the quality of a radio channel (or also called a link) formedbetween a UE and an antenna port.

An operation of a UE for a CSI-related procedure is described.

FIG. 10 is a flowchart illustrating an example of a CSI-relatedprocedure.

In order to perform one of uses of a CSI-RS described above, a terminal(e.g., user equipment (UE)) receives, from a base station (e.g., generalNode B or gNB), configuration information related to CSI through radioresource control (RRC) signaling (S110).

The configuration information related to the CSI may include at leastone of CSI-interference management (IM) resource-related information,CSI measurement configuration-related information, CSI resourceconfiguration-related information, CSI-RS resource-related information,or CSI report configuration-related information.

The CSI-IM resource-related information may include CSI-IM resourceinformation, CSI-IM resource set information, etc.

A CSI-IM resource set is identified by a CSI-IM resource set identifier(ID). One resource set includes at least one CSI-IM resource.

Each CSI-IM resource is identified by a CSI-IM resource ID.

The CSI resource configuration-related information defines a groupincluding at least one of a non zero power (NZP) CSI-RS resource set, aCSI-IM resource set, or a CSI-SSB resource set.

That is, the CSI resource configuration-related information includes aCSI-RS resource set list. The CSI-RS resource set list may include atleast one of an NZP CSI-RS resource set list, a CSI-IM resource setlist, or a CSI-SSB resource set list.

The CSI resource configuration-related information may be represented asa CSI-ResourceConfig IE.

The CSI-RS resource set is identified by a CSI-RS resource set ID. Oneresource set includes at least one CSI-RS resource.

Each CSI-RS resource is identified by a CSI-RS resource ID.

As in Table 5, parameters (e.g., a BM-related “repetition” parameter anda tracking-related “trs-Info” parameter) indicating the use of a CSI-RSfor each NZP CSI-RS resource set may be configured.

Table 5 illustrates an example of the NZP CSI-RS resource set IE.

TABLE 5 -- ASN1START -- TAG-NZP-CSI-RS-RESOURCESET-STARTNZP-CSI-RS-ResourceSet ::=   SEQUENCE {  nzp-CSI-ResourceSetId  NZP-CSI-RS-ResourceSetId,  nzp-CSI-RS-Resources   SEQUENCE (SIZE(1..maxNrofNZP-CSI- RS-ResourcesPerSet)) OF NZP-CSI-RS-ResourceId, repetition  ENUMERATED { on, off }  aperiodicTriggeringOffset INTEGER(0..4)  trs-Info ENUMERATED {true}  ... } --TAG-NZP-CSI-RS-RESOURCESET-STOP -- ASN1STOP

In Table 5, the repetition parameter is a parameter indicating whetherthe same beam is repeatedly transmitted, and indicates whether arepetition is “ON” or “OFF” for each NZP CSI-RS resource set. Atransmission (Tx) beam used in the present disclosure may be interpretedas the same meaning as a spatial domain transmission filter. A received(Rx) beam used in the present disclosure may be interpreted as the samemeaning as a spatial domain reception filter.

For example, if the repetition parameter in Table 5 is configured as“OFF”, a UE does not assume that an NZP CSI-RS resource(s) within aresource set is transmitted as the same Nrofports as the same DL spatialdomain transmission filter in all symbols.

Furthermore, the repetition parameter corresponding to a higher layerparameter corresponds to “CSI-RS-ResourceRep” of an L1 parameter.

The CSI report configuration-related information includes a reportconfiguration type (reportConfigType) parameter indicating a time domainbehavior and a report quantity (reportQuantity) parameter indicatingCSI-related quantity for reporting.

The time domain behavior may be periodic, aperiodic or semi-persistent.

Furthermore, the CSI report configuration-related information may berepresented as a CSI-ReportConfig IE. Table 6 below illustrates anexample of a CSI-ReportConfig IE.

TABLE 6 -- ASN1START -- TAG-CSI-RESOURCECONFIG-START CSI-ReportConfig::= SEQUENCE {  reportConfigId  CSI-ReportConfigId,  carrier ServCellIndex OPTIONAL, -- Need S  resourcesForChannelMeasurement    CSI-ResourceConfigId,  csi-IM-ResourcesForInterference    CSI-ResourceConfigId  OPTIONAL, -- Need R nzp-CSI-RS-ResourcesForInterference     CSI-ResourceConfigId  OPTIONAL,-- Need R  reportConfigType   CHOICE {   periodic    SEQUENCE {   reportSlotConfig    CSI-ReportPeriodicityAndOffset,   pucch-CSI-ResourceList    SEQUENCE (SIZE (1..maxNrofBWPs)) OFPUCCH-CSI-Resource   },   semiPersistentOnPUCCH     SEQUENCE {   reportSlotConfig     CSI-ReportPeriodicityAndOffset,   pucch-CSI-ResourceList     SEQUENCE (SIZE (1..maxNrofBWPs)) OFPUCCH-CSI-Resource   },   semiPersistentOnPUSCH     SEQUENCE {   reportSlotConfig     ENUMERATED {sl5, sl10, sl20, sl40, sl80, sl160,sl320},    reportSlotOffsetList    SEQUENCE (SIZE (1.. maxNrofUL-Allocations)) OF INTEGER(0..32),    p0alpha    P0-PUSCH-AlphaSetId   },  aperiodic    SEQUENCE {    reportSlotOffsetList    SEQUENCE (SIZE(1..maxNrofUL- Allocations)) OF INTEGER(0..32)    }  },  reportQuantity  CHOICE {   none    NULL,   cri-RI-PMI-CQI    NULL,   cri-RI-i1   NULL,   cri-RI-i1-CQI    SEQUENCE { pdsch-BundleSizeForCSI   ENUMERATED {n2, n4}  OPTIONAL   },   cri-RI-CQI    NULL,   cri-RSRP   NULL,   ssb-Index-RSRP    NULL,   cri-RI-LI-PMI-CQI    NULL  },

Furthermore, the UE measures CSI based on the configuration informationrelated to CSI (S120). The CSI measurement may include (1) a CSI-RSreception process S121 of the UE and (2) a process S122 of computing CSIthrough a received CSI-RS.

A sequence for a CSI-RS is generated by Equation 3 below. Aninitialization value of a pseudo-random sequence C(i) is defined byEquation 4.

$\begin{matrix}{{r(m)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}} & {〚{{Equation}\mspace{14mu} 3}〛} \\{c_{init} = {\left( {{2^{10}\left( {{N_{symb}^{slot}n_{s,f}^{\mu}} + l + 1} \right)\left( {{2n_{ID}} + 1} \right)} + n_{ID}} \right){mod}\; 2^{31}}} & {〚{{Equation}\mspace{14mu} 4}〛}\end{matrix}$

In Equations 3 and 4, n_(s,f) ^(μ) indicates a slot number within aradio frame, and a pseudo-random sequence generator is initialized asCint at the start of each OFDM symbol, that is, n_(s,f) ^(μ).

Furthermore, I is an OFDM symbol number within a slot. n_(ID) isidentical with a higher-layer parameter scram blingID.

Furthermore, in the CSI-RS, resource element (RE) mapping of a CSI-RSresource is configured in time and frequency domains by a higher layerparameter CSI-RS-Resource Mapping.

Table 7 illustrates an example of a CSI-RS-ResourceMapping IE.

TABLE 7 -- ASN1START -- TAG-CSI-RS-RESOURCEMAPPING-STARTCSI-RS-ResourceMapping ::=  SEQUENCE {  frequencyDomainAllocation CHOICE {   row1  BIT STRING (SIZE (4)),   row2  BIT STRING (SIZE (12)),  row4  BIT STRING (SIZE (3)),   other  BIT STRING (SIZE (6))  }, nrofPorts ENUMERATED {p1,p2,p4,p8,p12,p16,p24,p32}, firstOFDMSymbolInTimeDomain   INTEGER (0..13), firstOFDMSymbolInTimeDomain2   INTEGER (2..12)  cdm-Type ENUMERATED{noCDM, fd-CDM2, cdm4- FD2-TD2, cdm8-FD2-TD4},  density CHOICE {   dot5 ENUMERATED {evenPRBs, oddPRBs},   one  NULL,   three  NULL,   spare NULL  },  freqBand CSI-FrequencyOccupation,  ... }

In Table 7, density D indicates the density of CSI-RS resources measuredin an RE/port/physical resource block (PRB). nrofPorts indicates thenumber of antenna ports. Furthermore, the UE reports the measured CSI tothe base station (S130).

In this case, if the quantity of CSI-ReportConfig is configured as “none(or No report)” in Table 6, the UE may omit the report.

However, although the quantity is configured as “none (or No report)”,the UE may report the measured CSI to the base station.

A case where the quantity is configured as “none” is a case where anaperiodic TRS is triggered or a case where a repetition is configured.

In this case, the reporting of the UE may be defined to be omitted onlywhen the repetition is configured as “ON.”

In summary, if the repetition is configured as “ON” and “OFF”, CSIreporting may include all of “No report”, “SSB resource indicator(SSBRI) and L1-RSRP”, and “CSI-RS resource indicator (CRI) and L1-RSRP.”

Alternatively, if the repetition is “OFF”, the CSI reporting of “SSBRIand L1-RSRP” or “CRI and L1-RSRP” may be defined to be transmitted. Ifthe repetition is “ON”, the CSI reporting of “No report”, “SSBRI andL1-RSRP”, or “CRI and L1-RSRP” may be defined to be transmitted.

Beam Management (BM) Procedure

A beam management (BM) procedure defined in new radio (NR) is described.

The BM procedure corresponds to layer 1 (L1)/L2 (layer 2) procedures forobtaining and maintaining a set of base station (e.g., gNB or TRP)and/or a terminal (e.g., UE) beams which may be used for downlink (DL)and uplink (UL) transmission/reception, and may include the followingprocedure and terms.

-   -   Beam measurement: an operation of measuring characteristics of a        beamforming signal received by a base station or a UE.    -   Beam determination: an operation of selecting, by a base station        or a UE, its own transmission (Tx) beam/received (Rx) beam.    -   Beam sweeping: an operation of covering a space region by using        a Tx and/or Rx beam for a given time interval in a predetermined        manner.    -   Beam report: an operation of reporting, by a UE, information of        a beamformed signal based on beam measurement.

FIG. 11 is a concept view illustrating an example of a beam-relatedmeasurement model.

For beam measurement, an SS block (or SS/PBCH block (SSB)) or a channelstate information reference signal (CSI-RS) is used in the downlink. Asounding reference signal (SRS) is used in the uplink.

In RRC_CONNECTED, a UE measures multiple beams (or at least one beam) ofa cell. The UE may average measurement results (RSRP, RSRQ, SINR, etc.)in order to derive cell quality.

Accordingly, the UE may be configured to consider a sub-set of adetected beam(s).

Beam measurement-related filtering occurs in different two levels (in aphysical layer that derives beam quality and an RRC level in which cellquality is derived from multiple beams).

Cell quality from beam measurement is derived in the same manner withrespect to a serving cell(s) and a non-serving cell)(s).

If a UE is configured by a gNB to report measurement results for aspecific beam(s), a measurement report includes measurement results forX best beams. The beam measurement results may be reported asL1-reference signal received power (RSRP).

In FIG. 11, K beams (gNB beam 1, gNB beam 2, . . . , gNB beam k) 210 areconfigured for L3 mobility by a gNB, and correspond to the measurementof a synchronization signal (SS) block (SSB) or CSI-RS resource detectedby a UE in the L1.

In FIG. 11, layer 1 filtering 220 means internal layer 1 filtering of aninput measured at a point A.

Furthermore, in beam consolidation/selection 230, beam-specificmeasurements are integrated (or merged) in order to derive cell quality.

Layer 3 filtering 240 for cell quality means filtering performed onmeasurement provided at a point B.

A UE evaluates a reporting criterion whenever new measurement resultsare reported at least at points C and C1.

D corresponds to measurement report information (message) transmitted ata radio interface.

In L3 beam filtering 250, filtering is performed on measurement(beam-specific measurement) provided at a point A1.

In beam selection 260 for a beam report, X measurement values areselected in measurement provided at a point E.

F indicates beam measurement information included in a measurementreport (transmission) in a radio interface.

Furthermore, the BM procedure may be divided into (1) a DL BM procedureusing a synchronization signal (SS)/physical broadcast channel (PBCH)Block or CSI-RS and (2) an UL BM procedure using a sounding referencesignal (SRS).

Furthermore, each of the BM procedures may include Tx beam sweeping fordetermining a Tx beam and Rx beam sweeping for determining an Rx beam.

DL BM Procedure

First, the DL BM procedure is described.

The DL BM procedure may include (1) the transmission of beamformed DLreference signals (RSs) (e.g., CSI-RS or SS block (SSB)) of a basestation and (2) beam reporting of a UE.

In this case, the beam reporting may include a preferred DL RSidentifier (ID)(s) and L1-reference signal received power (RSRP)corresponding thereto.

The DL RS ID may be an SSB resource indicator (SSBRI) or a CSI-RSresource indicator (CRI).

FIG. 12 is a diagram illustrating an example of a DL BMprocedure-related Tx beam.

As illustrated in FIG. 12, an SSB beam and a CSI-RS beam may be used forbeam measurement.

In this case, a measurement metric is L1-RSRP for each resource/block.

An SSB may be used for coarse beam measurement, and a CSI-RS may be usedfor fine beam measurement.

Furthermore, the SSB may be used for both Tx beam sweeping and Rx beamsweeping.

A UE may perform the Rx beam sweeping using an SSB while changing an Rxbeam with respect to the same SSBRI across multiple SSB bursts.

In this case, one SS burst includes one or more SSBs, and one SS burstset includes one or more SSB bursts.

DL BM procedure using SSB

FIG. 13 is a flowchart illustrating an example of a DL BM procedureusing an SSB.

A configuration for a beam report using an SSB is performed uponCSI/beam configuration in an RRC connected state (or RRC connectedmode).

As in a CSI-ResourceConfig IE of Table 8, a BM configuration using anSSB is not separately defined, and an SSB is configured like a CSI-RSresource.

Table 8 illustrates an example of the CSI-ResourceConfig IE.

TABLE 8 -- ASN1START -- TAG-CSI-RESOURCECONFIG-START CSI-ResourceConfig::= SEQUENCE {  csi-ResourceConfigId CSI-ResourceConfigId, csi-RS-ResourceSetList  CHOICE {   nzp-CSI-RS-SSB    SEQUENCE {   nzp-CSI-RS-ResourceSetList     SEQUENCE (SIZE(1..maxNrofNZP-CSI-RS-ResourceSetsPerConfig)) OF NZP-CSI-RS-ResourceSetId OPTIONAL,    csi-SSB-ResourceSetList     SEQUENCE (SIZE(1..maxNrofCSI-SSB-ResourceSetsPerConfig)) OF CSI-SSB-ResourceSetId OPTIONAL   },   csi-IM-ResourceSetList   SEQUENCE (SIZE(1..maxNrofCSI-IM- ResourceSetsPerConfig)) OF CSI-IM-ResourceSetId  }, bwp-Id BWP-Id,  resourceType ENUMERATED { aperiodic, semiPersistent,periodic },  ... } -- TAG-CSI-RESOURCECONFIGTOADDMOD-STOP -- ASN1STOP

In Table 8, the csi-SSB-ResourceSetList parameter indicates a list ofSSB resources used for beam management and reporting in one resourceset. A UE receives, from a base station, a CSI-ResourceConfig IEincluding CSI-SSB-ResourceSetList including SSB resources used for BM(S410).

In this case, the SSB resource set may be configured with {SSBx1, SSBx2,SSBx3, SSBx4, . . . }.

An SSB index may be defined from 0 to 63.

Furthermore, the UE receives an SSB resource from the base station basedon the CSI-SSB-ResourceSetList (S420).

Furthermore, if CSI-RS reportConfig related to a report for an SSBRI andL1-RSRP has been configured, the UE (beam) reports, to the base station,the best SSBRI and L1-RSRP corresponding thereto (S430).

That is, if reportQuantity of the CSI-RS reportConfig IE is configuredas “ssb-Index-RSRP”, the UE reports the best SSBRI and the L1-RSRPcorresponding thereto to the base station.

Furthermore, if a CSI-RS resource is configured in an OFDM symbol(s)identical with an SS/PBCH block (SSB) and “QCL-TypeD” is applicable, theUE may assume that a CSI-RS and an SSB are quasi co-located from a“QCL-TypeD” viewpoint.

In this case, the QCL TypeD may mean that antenna ports have been QCLedfrom a spatial Rx parameter viewpoint. When the UE receives a pluralityof DL antenna ports having a QCL Type D relation, the same Rx beam maybe applied.

Furthermore, the UE does not expect that a CSI-RS will be configured inan RE that overlaps an RE of an SSB.

DL BM Procedure Using CSI-RS

If a UE is configured with NZP-CSI-RS-ResourceSet having a (higher layerparameter) repetition configured as “ON”, the UE may assume that atleast one CSI-RS resource within the NZP-CSI-RS-ResourceSet istransmitted as the same downlink spatial domain transmission filter.

That is, at least one CSI-RS resource within the NZP-CSI-RS-ResourceSetis transmitted through the same Tx beam.

In this case, the at least one CSI-RS resource within theNZP-CSI-RS-ResourceSet may be transmitted in different OFDM symbols ormay be transmitted in different frequency domains (i.e., through FDM).

A case where the at least one CSI-RS resource is FDMed is a case where aUE is a multi-panel UE.

Furthermore, a case where a repetition is configured as “ON” is relatedto an Rx beam sweeping procedure of a UE.

The UE does not expect that different periodicities will be received inperiodicityAndOffset in all CSI-RS resources withinNZP-CSI-RS-Resourceset.

Furthermore, if the repetition is configured as “OFF”, the UE does notassume that at least one CSI-RS resource within NZP-CSI-RS-ResourceSetis transmitted as the same downlink spatial domain transmission filter.

That is, the at least one CSI-RS resource within NZP-CSI-RS-ResourceSetis transmitted through different Tx beams.

A case where the repetition is configured as “OFF” is related to a Txbeam sweeping procedure of a base station.

Furthermore, the repetition parameter may be configured only withrespect to CSI-RS resource sets associated with CSI-ReportConfig havingthe reporting of L1 RSRP or “No Report (or None).”

If a UE is configured with CSI-ReportConfig having reportQuantityconfigured as “cri-RSRP” or “none” and CSI-ResourceConfig (higher layerparameter resourcesForChannelMeasurement) for channel measurement doesnot include a higher layer parameter “trs-Info” and includesNZP-CSI-RS-ResourceSet configured (repetition=ON) as a higher layerparameter “repetition”, the UE may be configured with only the samenumber of ports (1-port or 2-port) having a higher layer parameter“nrofPorts” with respect to all CSI-RS resources within theNZP-CSI-RS-ResourceSet.

More specifically, CSI-RS uses are described. If a repetition parameteris configured in a specific CSI-RS resource set and TRS_info is notconfigured, a CSI-RS is used for beam management.

Furthermore, if a repetition parameter is not configured and TRS_info isconfigured, a CSI-RS is used for a tracking reference signal (TRS).

Furthermore, if a repetition parameter is not configured and TRS_info isnot configured, a CSI-RS is used for CSI acquisition.

FIG. 14 is a diagram illustrating an example of a DL BM procedure usinga CSI-RS.

FIG. 14(a) illustrates an Rx beam determination (or refinement)procedure of a UE. FIG. 14(b) indicates a Tx beam determinationprocedure of a base station.

Furthermore, FIG. 14(a) corresponds to a case where the repetitionparameter is configured as “ON”, and FIG. 14(b) corresponds to a casewhere the repetition parameter is configured as “OFF.”

An Rx beam determination process of a UE is described with reference toFIGS. 14(a) and 15.

FIG. 15 is a flowchart illustrating an example of a received beamdetermination process of a UE.

The UE receives, from a base station, an NZP CSI-RS resource set IEincluding a higher layer parameter repetition through RRC signaling(S610).

In this case, the repetition parameter is configured as “ON.”

Furthermore, the UE repeatedly receives a resource(s) within a CSI-RSresource set configured as a repetition “ON” in different OFDM symbolsthrough the same Tx beam (or DL spatial domain transmission filter) ofthe base station (S620).

Accordingly, the UE determines its own Rx beam (S630).

In this case, the UE omits a CSI report or transmits, to the basestation, a CSI report including a CRI/L1-RSRP (S640).

In this case, reportQuantity of the CSI report config may be configuredas “No report (or None)” or “CRI+L1-RSRP.”

That is, if a repetition “ON” is configured, the UE may omit a CSIreport. Alternatively, the UE may report ID information (CRI) for a beampair-related preference beam and a corresponding quality value(L1-RSRP).

A Tx beam determination process of a base station is described withreference to FIGS. 14(b) and 16.

FIG. 16 is a flowchart illustrating an example of a method ofdetermining, by a base station, a transmission beam.

A UE receives, from a base station, an NZP CSI-RS resource set IEincluding a higher layer parameter repetition through RRC signaling(S710).

In this case, the repetition parameter is configured as “OFF”, and isrelated to a Tx beam sweeping procedure of the base station.

Furthermore, the UE receives resources within the CSI-RS resource setconfigured as the repetition “OFF” through different Tx beams (DLspatial domain transmission filters) of the base station (S720).

Furthermore, the UE selects (or determines) the best beam (S740), andreports an ID for the selected beam and related quality information(e.g., L1-RSRP) to the base station (S740).

In this case, reportQuantity of the CSI report config may be configuredas “CRI+L1-RSRP.”

That is, the UE reports a CRI and corresponding L1-RSRP to the basestation if a CSI-RS is transmitted for BM.

FIG. 17 is a diagram illustrating an example of resource allocation intime and frequency domains related to the operation of FIG. 14.

That is, it may be seen that if the repetition “ON” has been configuredin a CSI-RS resource set, a plurality of CSI-RS resources is repeatedlyused by applying the same Tx beam, and if a repetition “OFF” has beenconfigured in the CSI-RS resource set, different CSI-RS resources aretransmitted through different Tx beams.

DL BM-Related Beam Indication

A UE may be RRC-configured with a list of a maximum of M candidatetransmission configuration indication (TCI) states for an object of atleast quasi co-location (QCL) indication. In this case, M may be 64.

Each of the TCI states may be configured as one RS set.

Each ID of a DL RS for at least a spatial QCL purpose (QCL Type D)within the RS set may refer to one of DL RS types, such as an SSB, aP-CSI RS, an SP-CSI RS, and an A-CSI RS.

The initialization/update of an ID of a DL RS(s) within the RS set usedfor the at least spatial QCL purpose may be performed through at leastexplicit signaling.

Table 9 illustrates an example of a TCI-State IE.

The TCI-State IE associates one or two DL reference signals (RS) with acorresponding quasi co-location (QCL) type.

TABLE 9 -- ASN1START -- TAG-TCI-STATE-START TCI-State ::= SEQUENCE { tci-StateId  TCI-StateId,  qcl-Type1  QCL-Info,  qcl-Type2  QCL-Info ... } QCL-Info ::= SEQUENCE {  cell ServCellIndex  bwp-Id  BWP-Id referenceSignal   CHOICE {   csi-rs   NZP-CSI-RS-ResourceId,   ssb  SSB-Index  },  qcl-Type  ENUMERATED {typeA, typeB, typeC, typeD},  ...} -- TAG-TCI-STATE-STOP -- ASN1STOP

In Table 9, the bwp-ld parameter indicates a DL BWP where an RS islocated. The cell parameter indicates a carrier where an RS is located.The reference signal parameter indicates a reference antenna port(s)that becomes the source of a quasi co-location for a correspondingtarget antenna port(s) or a reference signal including the referenceantenna port(s). A target antenna port(s) may be a CSI-RS, a PDCCH DMRS,or a PDSCH DMRS. For example, in order to indicate QCL reference RSinformation for an NZP CSI-RS, a corresponding TCI state ID may beindicated in NZP CSI-RS resource configuration information. Furthermore,for example, in order to indicate QCL reference information for a PDCCHDMRS antenna port(s), a TCI state ID may be indicated in a CORESETconfiguration. Furthermore, for example, in order to indicate QCLreference information for a PDSCH DMRS antenna port(s), a TCI state IDmay be indicated through DCI.

Quasi-Co Location (QCL)

An antenna port is defined so that a channel on which a symbol on anantenna port is carried is inferred from a channel on which anothersymbol on the same antenna port is carried. If the properties of achannel on which a symbol on one antenna port is carried can be derivedfrom a channel on which a symbol on another antenna port is carried, thetwo antenna ports may be said to have a quasi co-located or quasico-location (QC/QCL) relation.

In this case, the properties of the channel includes one or more ofdelay spread, Doppler spread, a frequency shift, average received power,received timing, and a spatial RX parameter. In this case, the spatialRx parameter means a spatial (reception) channel property parameter,such as an angle of arrival.

In order to decode a PDSCH according to a detected PDCCH having intendedDCI with respect to a corresponding UE and a given serving cell, a UEmay be configured with a list of up to M TCI-State configurations withinhigher layer parameter PDSCH-Config. The M depends on a UE capability.

Each of the TCI-States includes a parameter for configuring a quasico-location relation between one or two DL reference signals and theDM-RS port of a PDSCH.

The quasi co-location relation is configured as a higher layer parameterqcl-Type1 for a first DL RS and a higher layer parameter qcl-Type2 (ifconfigured) for a second DL RS.

In the case of the two DL RSs, QCL types are not the same regardless ofwhether reference is the same DL RS or different DL RSs.

A quasi co-location type corresponding to each DL RS is given by ahigher layer parameter qcl-Type of QCL-Info, and may take one of thefollowing values:

-   -   “QCL-TypeA”: {Doppler shift, Doppler spread, average delay,        delay spread}    -   “QCL-TypeB”: {Doppler shift, Doppler spread}    -   “QCL-TypeC”: {Doppler shift, average delay}    -   “QCL-TypeD”: {Spatial Rx parameter}

For example, if a target antenna port is a specific NZP CSI-RS, it maybe indicated/configured that corresponding NZP CSI-RS antenna ports havebeen QCLed with a specific TRS from a QCL-Type A viewpoint and with aspecific SSB from a QCL-Type D viewpoint. A UE configured with such anindication/configuration may receive a corresponding NZP CSI-RS by usingDoppler, delay value measured in a QCL-TypeA TRS, and may apply, to thereception of the corresponding NZP CSI-RS, an Rx beam used for thereception of a QCL-TypeD SSB.

The UE receives an activation command used to map up to eight TCI statesto the codepoint of a DCI field “Transmission Configuration Indication.”

Beam failure detection (BFD) and beam failure recovery (BFR) procedure

A beam failure detection and beam failure recovery procedure isdescribed below.

In a beamformed system, a radio link failure (RLF) may frequently occurdue to the rotation, movement or beam blockage of a UE.

Accordingly, in order to prevent a frequent RLF from occurring, BFR issupported in NR.

BFR is similar to a radio link failure recovery procedure, and may besupported if a UE is aware of a new candidate beam(s).

For convenience of understanding, (1) a radio link monitoring procedureand (2) a link recovery procedure are first described in brief.

Radio Link Monitoring

Downlink radio link quality of a primary cell is monitored by a UE forthe purpose of indicating an out-of-sync or in-sync state for higherlayers.

A cell used in the present disclosure may also be represented as acomponent carrier, a carrier, a BW, etc.

A UE does not need to monitor downlink radio link quality in a DL BWPother than an active DL BWP on a primary cell.

The UE may be configured with respect to each DL BWP of SpCell having aset of resource indices through a corresponding set of (higher layerparameter) RadioLinkMonitoringRS for radio link monitoring by a higherlayer parameter failureDetectionResources.

A higher layer parameter RadioLinkMonitoringRS having a CSI-RS resourceconfiguration index (csi-RS-Index) or an SS/PBCH block index (ssb-lndex)is provided to the UE.

If RadioLinkMonitoringRS is not provided to a UE and the UE is providedwith a TCI-state for a PDCCH including one or more RSs including one ormore of a CSI-RS and/or an SS/PBCH block,

-   -   if an active TCI-state for the PDCCH includes only one RS, the        UE uses, for radio link monitoring, an RS provided for the        active TCI-state for the PDCCH.    -   If the active TCI-state for the PDCCH includes two RSs, the UE        expects that one RS has QCL-TypeD and will use one RS for radio        link monitoring. In this case, the UE does not expect that both        the RSs will have QCL-TypeD.    -   The UE does not use an aperiodic RS for radio link monitoring.

Table 10 below illustrates an example of an RadioLinkMonitoringConfigIE.

The RadioLinkMonitoringConfig IE is used to configure radio linkmonitoring for the detection of a beam failure and/or a cell radio linkfailure.

TABLE 10 -- ASN1START -- TAG-RADIOLINKMONITORINGCONFIG-STARTRadioLinkMonitoringConfig ::= SEQUENCE { failureDetectionResourcesToAddModList    SEQUENCE(SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS OPTIONAL, -- Need N  failureDetectionResourcesToReleaseList    SEQUENCE(SIZE(1..maxNrofFailureDetectionResources)) OF RadioLinkMonitoringRS-Id OPTIONAL,-- Need N  beamFailureInstanceMaxCount    ENUMERATED {n1, n2,n3, n4, n5, n6, n8, n10}   OPTIONAL, -- Need S beamFailureDetectionTimer    ENUMERATED {pbfd1, pbfd2, pbfd3, pbfd4,pbfd5, pbfd6, pbfd8, pbfd10}     OPTIONAL, --Need R  ... }RadioLinkMonitoringRS ::= SEQUENCE {  radioLinkMonitoringRS-Id  RadioLinkMonitoringRS-Id,  purpose  ENUMERATED {beam Failure, rlf,both},  detectionResource  CHOICE {   ssb-Index  SSB-Index,  csi-RS-Index  NZP-CSI-RS-ResourceId  },  ... } --TAG-RADIOLINKMONITORINGCONFIG-STOP -- ASN1STOP

In Table 10, the beamFailureDetectionTimer parameter is a timer for beamfailure detection. The beamFailurelnstanceMaxCount parameter indicatesthat a UE triggers beam failure recovery after how many beam failureevents.

The value n1 corresponds to one beam failure instance, and the value n2corresponds to two beam failure instances. If a network reconfigures acorresponding field, a UE resets a counter related toon-goingbeamFailureDetectionTimer and beam FailureInstanceMaxCount.

If a corresponding field is not present, the UE does not trigger beamfailure recovery.

Table 11 illustrates an example of an BeamFailureRecoveryConfig IE.

The BeamFailureRecoveryConfig IE is used to configure, in a UE, RACHresources and candidate beams for beam failure recovery in a beamfailure detection situation.

TABLE 11 -- ASN1START -- TAG-BEAM-FAILURE-RECOVERY-CONFIG-STARTBeamFailureRecoveryConfig ::=   SEQUENCE {  rootSequencelndex-BFR  INTEGER (0..137)  rach-ConfigBFR   RACH-ConfigGeneric rsrp-ThresholdSSB  RSRP-Range  candidateBeamRSList    SEQUENCE(SIZE(1..maxNrofCandidateBeams)) OF PRACH-ResourceDedicatedBFR OPTIONAL, -- Need M  ssb-perRACH-Occasion   ENUMERATED {oneEighth,oneFourth, oneHalf, one, two, four, eight, sixteen}   OPTIONAL, -- NeedM  ra-ssb-OccasionMaskIndex   INTEGER (0..15)  recoverySearchSpaceId  SearchSpaceId  ra-Prioritization  RA-Prioritization beamFailureRecoveryTimer   ENUMERATED {ms10, ms20, ms40, ms60, ms80,ms100, ms150, ms200}     OPTIONAL, -- Need M  ... }PRACH-ResourceDedicatedBFR ::=    CHOICE {  ssb  BFR-SSB-Resource, csi-RS  BFR-CSIRS-Resource } BFR-SSB-Resource ::= SEQUENCE {  ssbSSB-Index,  ra-PreambleIndex INTEGER (0..63),  ... } BFR-CSIRS-Resource::=  SEQUENCE {  csi-RS NZP-CSI-RS-ResourceId,  ra-OccasionList SEQUENCE (SIZE(1..maxRA- OccasionsPerCSIRS)) OF INTEGER(0..maxRA-Occasions-1) OPTIONAL, -- Need R  ra-PreambleIndex INTEGER(0..63)  ... } -- TAG-BEAM-FAILURE-RECOVERY-CONFIG-STOP -- ASN1STOP

In Table 11, the beamFailureRecoveryTimer parameter is a parameterindicating a timer for beam failure recovery, and a value thereof may beset as ms. The candidateBeamRSList parameter indicates a list ofreference signals (CSI-RSs and/or SSBs) for identifying random access(RA) parameters associated with candidate beams for recovery.

The RecoverySearchSpaceId parameter indicates a search space used for aBFR random access response (RAR).

When radio link quality is poorer than a threshold value Qout for allresources within a set of resources for radio link monitoring, thephysical layer of a UE indicates out-of-sync through a higher layer inframes in which radio link quality is evaluated.

When radio link quality for a given resource within a resource set forradio link monitoring is better than a threshold value Qin, the physicallayer of the UE indicates in-sync through a higher layer in a frame inwhich radio link quality is evaluated.

Link Recovery Procedure

With respect to a serving cell, a UE is provided with a q0 set ofperiodic CSI-RS resource configuration indices by a higher layerparameter failureDetectionResources and a q1 set of periodic CSI-RSresource configuration indices and/or SS/PBCH block indices bycandidateBeamRSList for radio link quality measurement on a servingcell.

If a UE is not provided with failureDetectionResources, the UEdetermines the q0 set to include an SS/PBCH block index and a periodicCSI-RS resource configuration index having the same value as an RS indexwithin an RS set indicated by a TCI state for each control resource setused for its own PDCCH monitoring.

A threshold value Qout_LR corresponds to a default value of a higherlayer parameter rImInSyncOutOfSyncThreshold and a value provided by ahigher layer parameter rsrp-ThresholdSSB.

The physical layer of the UE evaluates radio link quality based on theq0 set of a resource configuration for the threshold Qout_LR.

With respect to the set q0, the UE evaluates radio link quality based ononly periodic CSI-RS resource configuration and SSBs quasi co-locatedwith the DM_RS reception of a PDCCH, which is monitored by the UE.

The UE applies a Qin_LR threshold value to an L1-RSRP measurement valueobtained from an SS/PBCH block.

After scaling each CSI-RS received power into a value provided bypowerControlOffsetSS, the UE applies the Qin_LR threshold value to theL1-RSRP measurement value obtained with respect to the CSI-RS resource.

The physical layer of the UE provides indication to a higher layer whenradio link quality of all corresponding resource configurations within aset used for the UE to evaluate the radio link quality is poorer thanthe threshold value Qout_LR.

The physical layer provides notification to a higher layer when theradio link quality is poorer than the threshold Qout_LR havingperiodicity determined as a maximum value between the shortestperiodicity of an SS/PBCH block and 2 msec in a periodic CSI-RSconfiguration or in the q0 set used for the UE to evaluate the radiolink quality.

In response to a request from a higher layer, the UE provides the higherlayer with a periodic CSI-RS configuration index and/or SS/PBCH blockindex from the q1 set and a corresponding L1-RSRP measurement valueequal to or identical with a corresponding threshold value.

A UE may be provided with a control resource set through a link with asearch space set provided by recoverySearchSpaceId in order to monitor aPDCCH in the control resource set.

If the UE is provided with recoverySearchSpaceId, the UE does not expectthat another search space will be provided in order to monitor a PDCCHin a control resource set associated with a search space provided byrecoverySearchSpaceId.

The aforementioned beam failure detection (BFD) and beam failurerecovery (BFR) procedure is subsequently described.

When a beam failure is detected on a serving SSB or a CSI-RS(s), a beamfailure recovery procedure used to indicate a new SSB or CSI-RS for aserving base station may be configured by RRC.

RRC configures BeamFailureRecoveryConfig for a beam failure detectionand recovery procedure.

FIG. 18 is a flowchart illustrating an example of a beam failurerecovery procedure.

The BFR procedure may include (1) a beam failure detection step S1410,(2) a new beam identification step S1420, (3) a beam failure recoveryrequest (BFRQ) step S1430 and (4) the step S1440 of monitoring aresponse to BFRQ from a base station.

In this case, a PRACH preamble or a PUCCH may be used for the step (3),that is, for BFRQ transmission.

The step (1), that is, the beam failure detection, is more specificallyis described.

When the block error rates (BLERs) of all serving beams are a thresholdor more, this is called a beam failure instance.

RSs(qo) to be monitored by a UE is explicitly configured by RRC or isimplicitly determined by a beam RS for a control channel.

The indication of a beam failure instance is periodic through a higherlayer, and an indication interval is determined by the lowestperiodicity of beam failure detection (BFD) RSs.

If evaluation is lower than a beam failure instance BLER threshold, anindication through a higher layer is not performed.

If N consecutive beam failure instances occur, a beam failure isdeclared.

In this case, N is a NrofBeamFailurelnstance parameter configured byRRC.

1-port CSI-RS and SSB is supported for a BFD RS set.

Next, the step (2), that is, new beam indication is described.

A network NW may configure one or multiple PRACH resources/sequencesfora UE.

A PRACH sequence is mapped to at least one new candidate beam.

The UE selects a new beam among candidate beams each having L1-RSRP setto be equal to or higher than a threshold set by RRC, and transmits aPRACH through the selected beam. In this case, which beam is selected bythe UE may be a UE implementation issue.

Next, the steps (3) and (4), that is, BFRQ transmission and themonitoring of a response to BFRQ are is described.

A UE may be configured with a dedicated CORESET by RRC in order tomonitor time duration of a window and a response to BFRQ from a basestation.

The UE starts monitoring after 4 slots of PRACH transmission.

The UE assumes that the dedicated CORESET has been spatially QCLed withthe DL RS of a UE-identified candidate beam in a beam failure recoveryrequest.

If a timer expires or the number of PRACH transmissions reaches amaximum number, the UE stops the BFR procedure.

In this case, a maximum number and timer of PRACH transmissions isconfigured by RRC.

Slot Aggregation in NR

In Rel-15 new ratio (NR), a method of increasing reliability byrepetitively transmitting one transport block (TB) to one layer in aplurality of contiguous slots has been standardized as described in apredefined rule (e.g., 3GPP TS 38.214, 5.1.2.1., 6.1.2.1.) with respectto the transmission of a physical downlink shared channel (PDSCH) and aphysical uplink shared channel (PUSCH), that is, physical channelscapable of transmitting data and control information. In this case, eachof aggregationFactorDL and aggregationFactorUL may have one value of{2,4,8} (refer to 3GPP TS 38.331). That is, the same data may berepeatedly transmitted in contiguous 2 slots, 4 slots, or 8 slots.

If a UE is configured with aggregationFactorDL>1, the same symbolallocation may also be applied to aggregationFactorDL contiguous slots.The UE may expect that a TB is repeated within each symbol allocationwithin the AggregationFactorDL contiguous slots and a PDSCH will belimited to a single transmission layer. A redundancy version to beapplied to an n-th transmission occasion of the TB may be determinedaccording to Table 12.

Table 12 illustrates a redundancy version applied whenaggregationFactorDL>1.

TABLE 12 rv_(id) indicated by rv_(id) applied to an n^(th) transmissionoccasion DCI that schedules n mod n mod n mod n mod a PDSCH 4 = 0 4 = 14 = 2 4 = 3 0 0 2 3 1 2 2 3 1 0 3 3 1 0 2 1 1 0 2 3

Table 13 illustrates a redundancy version when aggregationFactorUL>1.

TABLE 13 rv_(id) indicated by rv_(id) applied to an n^(th) transmissionoccasion DCI that schedules n mod n mod n mod n mod a PUSCH 4 = 0 4 = 14 = 2 4 = 3 0 0 2 3 1 2 2 3 1 0 3 3 1 0 2 1 1 0 2 3

Furthermore, in NR, the same uplink control information (UCI) may berepeatedly transmitted in a plurality of contiguous slots (in whichavailable UL resource is present) with respect to a physical uplinkcontrol channel (PUCCH), that is, a channel in which uplink controlinformation is transmitted, as described in a predefined rule (e.g.,3GPP TS 38.213, 9.2.6.).

As described above, if a multi-slot PUSCH in which repetitivetransmissions for a TB are performed and/or a multi-slot PUCCH in whichrepetitive transmissions for UCI are performed is configured and/orindicated, when a collision occurs between a PUSCH and/or PUCCH resourceand another PUCCH resource and/or PUSCH resource (transmission isindicated in the same symbol and/or slot) during repetitivetransmissions in contiguous slots in which an available uplink (UL)resource is present, an operation of not transmitting the TB and/or theUCI in a corresponding slot or piggybacking (or multiplexing) andtransmitting the TB and/or the UCI in a resource in which a collisionhas occurred, etc. is defined.

Cell/Base Station Diversity Improvement

In a resource of ultra-reliable, low latency communications (URLLC)service, to secure reliability in relation to a radio channel state is achallenging issue. In general, a requirement for a radio section ofreliability are defined so that the probability that a packet of y bytesneeds to be transmitted within x msec is z % or more (e.g., x=1, y=100,z=99.999). In order to satisfy such a requirement, the most difficultpoint is that the capability of a corresponding channel does notfundamentally satisfy the condition because the quality of a radiochannel itself is too deteriorated.

The present disclosure is to solve the issue by obtaining cell and/orbase station diversity in such an environment. That is, the presentdisclosure is to satisfy reliability requirement by allowing multiplecells, base stations and/or transmission points (TPs) to transmit thesame data so that a UE can receive information from another cell and/orbase station having a relatively good channel state although a radiochannel for a specific cell, base station and/or TP is too deteriorated.Hereinafter, in the present disclosure, as a method of obtaining celland/or base station diversity, cell cycling downlink transmission,cross-cell scheduling, UE demodulation, downlink control signaling forindicating the sequence of TPs, symbol muting for cell cycling, and a UEsynchronization operation are sequentially described.

Cell Cycling Downlink Transmission

In downlink transmission, a plurality of cells, base stations and/or TPsmay alternately perform data transmission to a specific UE in an agreedsequence between a base station and the UE. In the consecutivetransmission, downlink scheduling information (downlink grant) has acharacteristic in that it is signaled to a UE only once.

If this method is applied, various methods may be considered inconfiguring a signal to be transmitted for each cell, base stationand/or TP. For example, a method of repetitively transmitting the samesignal in each cell, base station and/or TP may be considered. That is,this method is a method of sequentially and repetitively transmitting,by each cell, base station and/or TP, signals to which the same channelcoding has been applied from the same information bit.

And/or a method of performing coding at a lower coding rate inproportion to the number of participating cells, base stations and/orTPs from one information bit and dividing and transmitting, by the cell,the base station and/or the TP, encoded bits may also be considered.Such methods are summarized as follows.

1) Extended Channel Coding

This is a scheme of applying channel coding so that different cells,base stations and/or TPs can decode different parity bits of an encodedcodeword in one decoder. The scheme may be divided as follows dependingon whether an information bit is repeated.

(1) Information bit repetition channel coding: this is a method ofidentically setting, by different cells, base stations and/or TPs,information bits within a transport block (TB) and differently settingparity bits. By designating a parity bit to be previously used uponencoding, parity bits of different cells, base stations and/or TPs donot overlap.

This may be similar when the TB of each cell, base station and/or TP isconsidered as the retransmission of an incremental (IR)-hybrid automaticrepeat and request (HARQ). For example, if the number of cells, basestations and/or TPs is N, parity bits generated upon encoding aredivided into N groups and only the parity bit within the group is usedin each cell, base station and/or TP. A device that has received acorresponding signal is aware of parity group information transmitted ineach cell, base station and/or TP, and each cell, base station and/or TPmay arrange parity bits within a received TB and perform decoding foreach group.

(2) Information bit non-repetition channel coding: this is a method ofgenerating, by different cells, base stations and/or TPs, one group TBby grouping TBs and performing channel coding based on a group TB size.The corresponding scheme has an advantage in that a channel coding gainis the greatest and has a disadvantage in that decoding is possible onlywhen all the TBs of each cell, base station and/or TP are received.

2) Separated Channel Coding

(1) Repetition-based LLR combining: this is a scheme for applying, bydifferent cells, base stations and/or TPs, a TB having the same size andrepeatedly transmitting the same TB. A device that has received acorresponding signal obtains a log likelihood ratio (LLR) value byindependently performing a process prior to decoding. The sum value ofcomputed LLR values may be used as an input value for one decoder.

(2) Hard value combining: this is a scheme for applying, differentcells, base stations and/or TPs, a TB having the same size andrepeatedly transmitting the same TB. Furthermore, the different cells,base stations and/or TPs independently decode received TBs and determinethat the reception of signals is successful when succeeding in thedecoding any one of the TBs of each cell, base station and/or TP.

Cross-Cell Scheduling

A network (or base station) schedules scheduling information for aplurality of contiguous subframes in the first subframe only once. Indownlink transmission in the plurality of contiguous subframes, aplurality of cells, base stations and/or TPs participates in thetransmission.

In the application of cross-cell scheduling, information for whether toperform downlink scheduling on a plurality of contiguous subframes maybe previously signaled through a layer 2 and/or layer 3 message or maybe transmitted to a UE through a layer 1 message along with downlinkscheduling information. And/or if a UE can be previously aware thatURLLC information will be transmitted, this information may be omitted.

In the application of cross-cell scheduling, a rule by which a UE doesnot perform a behavior (e.g., blind decoding) of finding a DL grantduring contiguous N subframes after receiving the DL grant in a specificsubframe may be defined, agreed and/or configured.

FIGS. 19 and 20 illustrate examples of cross-cell scheduling. FIG. 19illustrates an example in which a resource scheduled in the firstsubframe continues for a plurality of contiguous subframes. FIG. 20illustrates another example in which a resource scheduled in the firstsubframe is hopped according to a predetermined rule during a pluralityof contiguous subframes. If resource hopping occurs, there is anadvantage in that a higher frequency diversity gain can be obtained inthe situation in which channel quality measurement for multiple cells isnot sufficiently handled. If both the case where resource hopping occursand the case where resource hopping does not occur are supported,signaling related to the hopping may be indicated for a UE as physicallayer, layer 2, and/or, layer 3 information.

In the description of the cross-cell scheduling method, a basic unit inwhich transmission is switched between cells, base stations and/or TPsis assumed to be a subframe, but is not limited thereto. For example, ascheme for switching transmission in a plurality of symbol group unitsis possible. FIG. 21 illustrates a scheme for grouping a plurality ofTPs by three symbols and alternately performing transmission.

In the present disclosure, for convenience of description, a unit time(e.g., a subframe, N symbols) in which each cell, base station and/or TPalternately performs transmission for each base station is called a timeunit (TU).

UE Demodulation Behavior

UEs that have received downlink allocation information for contiguousTUs independently use reference signals transmitted in TUs in thedemodulation of downlink data channels. An integrated estimation scheme(e.g., channel interpolation techniques) is not applied between the TUsin channel estimation.

A UE demodulation behavior may assume that a reference signal istransmitted in each TU. In this case, since different cells, basestations and/or TPs perform transmission in different TUs, there is arestriction in that channel estimation independently occurs. FIG. 22illustrates an example in which 1 TU=three symbols. As in FIG. 22, if areference signal is transmitted in a symbol 3, 6, 9, a channelestimation value using a reference signal in the symbol 3 is used forthe demodulation of {1, 2} symbols. Likewise, a channel estimation valueusing a reference signal in the symbol 9 with respect to symbol 6, {7,8} symbols is used with respect to {4, 5} symbols. In this case, uponchannel estimation, a channel interpolation scheme may not be applied toreference signals transmitted in each TU.

DL Control Signaling for Indicating the Sequence of TPs

A network (or base station) may signal, to a UE, one or more of piecesof the following information (a) to (b) with respect to a plurality ofcells, base stations and/or TPs which will participate in downlink datatransmission.

(a) cell identifier (ID), base station ID and/or TP ID informationtransmitted in each TU

(b) physical resource location information and/or sequence informationof a reference signal transmitted in each TU

(c) indicator of quasi co-location (QCL) with other reference signalstransmitted in each TU with respect to a reference signal (transmittedin a serving cell)

Physical resource locations (time and/or frequency) and/or sequencescorresponding to different cell IDs and/or TP IDs may be used becausereference signals transmitted in TUs are transmitted in different cellsand/or TP. Accordingly, in order to receive the reference signals andperform channel estimation, a UE may need to signal the information. Forexample, as in (a), a participating cell ID and/or TP ID may be directlytransmitted. And/or as in (b), the scrambling ID of a reference signalmay be transmitted. In this case, a network (or base station) may notifythe UE of scrambling ID set information of reference signalsconsecutively transmitted through a layer 1, layer 2 and/or layer 3control message. And/or as in (c), by indicating whether QCL isperformed between reference signals or between antenna ports, whetherthe same base station, cell and/or TP participates in transmission ineach TU may be notified.

In applying the proposal, only information for reference signals exceptinformation for the first TU may be subsequently signaled because a cellID and/or TP ID regulated for a cell and/or a TP (e.g., a serving cell)that provides a DL grant and a scrambling ID for a reference signal canbe used in the first TU.

Symbol Muting for Cell Cycling

A base station, a cell and/or a TP that transmits contiguous TUs maymute a symbol at a TU boundary point.

As Example 1, upon N consecutive TU transmission, the last symbols ofthe 1^(st) to (N−1)^(th)) TUs may be muted.

As Example 2, upon N consecutive TU transmission, the first symbols ofthe 2^(nd) to N^(th) TUs may be muted.

This method corresponds to contents proposed because interference mayoccur due to a collision between symbols at a TU boundary because timesynchronization is different for each TU if a UE receives signals frombase stations physically located at different distance.

The muting operation may be variously interpreted as transmissionomission for a specific physical signal or channel, or a puncturingoperation and/or a rate matching operation for resource elementscorresponding to a symbol corresponding to a specific physical channel.

FIG. 23 illustrates an example in which the last symbol of a datachannel is punctured or rate-matched as in Example 1.

FIG. 24 illustrates an example in which the transmission of a controlchannel transmitted in the first symbol of a subframe which isconsecutively and subsequently transmitted is omitted in a TP1 in whichthe corresponding subframe is transmitted, as in Example 2.

UE Synchronization

Method 1: a network (or base station) may transmit, to a UE, a list ofbase stations, cells and/or TPs having the possibility that it canperform consecutive transmission through a layer 2 and/or layer 3message. The UE that has received the corresponding message maypreviously store configuration values for making time and/or frequencysynchronization in reparation for a case where base stations, cellsand/or TPs included in the corresponding list will perform consecutivetransmission.

Method 2: when receiving a data channel transmitted in each TU, a UE mayadjust time and/or frequency synchronization for each TU by using areference signal transmitted in the corresponding TU.

In Methods 1 and 2, time and/or frequency synchronization need to beseparately performed because different base stations, cells and/or TPsare transmitted in different TUs. To this end, Method 1 is a scheme forpreviously providing notification of a corresponding base station, celland/or TP candidate group so that a synchronization signal can bereceived. Method 2 is a scheme for performing an adjustment operation ona difference between synchronizations compared to a previous basestation, cell and/or TP by using a reference signal transmitted in acorresponding TU.

Methods 1 and 2 may be used separately or together. If the methods areused together, Method 2 may be used for fine adjustment forsynchronization.

The present disclosure has been described based on a downlink sharedchannel (PDSCH), but may also be applied to an uplink channel (e.g., aPUSCH, a PUCCH, or a PRACH) in addition to a physical downlink controlchannel (PDCCH).

In the present disclosure, transmission at different base stations,cells and/or TPs physically spaced apart from one another, but thepresent disclosure is not limited thereto. For example, the presentdisclosure may also be applied to transmission in different panelsand/or beams in the same base station. In the present disclosure, ifmultiple frequency bands (carriers) are operated in base stationsphysically implemented at the same location, the method of the presentdisclosure may be applied by operating each frequency band as anindependent logical cell. That is, the present disclosure may beextended to a technology for cyclic transmission in an agreed sequenceat different carriers in order to obtain a frequency diversity gain.Likewise, the present disclosure may also be extended to differentcarriers of different base stations, cells and/or TPs.

In the present disclosure, “/” may mean “and” or “or” depending oncontext. For example, in the present disclosure, “A/B” may beinterpreted as the same meaning as “includes at least one of A or B.” Inthe present disclosure, an idea is described based on a PDSCH, but isnot limited thereto. The same and/or similar method may also be appliedto a PDCCH configured in a plurality of time units (TU).

In the proposed method, one data packet (e.g., TB, code block group(CBG)) configured in a specific unit is repetitively transmitted acrossseveral time units (TUs), but a transmission source (e.g., TP, beam orpanel) is different each TU or TU group so that a transmission source isdifferent for each TU (group) in addition to time diversity andcombining diversity by repetitive transmission and a QCL reference (orsource) necessary for (fine synchronization and) channel estimation by aUE is different for each TU (or TU group).

In other words, the present disclosure proposes a method of obtainingtime diversity and combining diversity and enabling more accuratechannel estimation if one data packet is repeatedly transmitted acrossmultiple TUs in the proposed methods.

Hereinafter, the present disclosure proposes a method of mapping aplurality of QCL references and/or transmission sources in a TU (or TUgroup) unit. In particular, the present disclosure proposes a methodand/or a rule for mapping a plurality of transmission sources and TUsbased on a total number N of scheduled TUs and a total number M oftransmission sources (a total number of QCL references and/or a totalnumber of TCIs).

Hereinafter, the present disclosure assumes a TU=a slot (or slot group),for convenience of description, but is not limited thereto. It isevident that the present disclosure may also be applied to a case wherea TU is configured in a symbol (or symbol group) level. Alternatively,in the present disclosure, a TU (or TU group) may be defined, agreedand/or configured in various units, such as a slot (or slot group) andone or more symbols. Furthermore, information for such a unit may beseparately signaled to a UE. Furthermore, in the present disclosure, aterm “time unit (TU)” may be used as various terms, such as atransmission occasion and a repetition occasion and a transmission unit.

Prior to the description of a detailed method, a representativeinformation exchange and/or operation between a base station and a UE ifthe present disclosure is applied, is as follows.

A base station may configure and/or indicate, in a UE, multi-TU PDSCHtransmission and a TU group configuration for a corresponding multi-TUPDSCH. Next, the base station may configure and/or indicate, in the UE,QCL reference RS information to be applied (to a specific QCL parameterset) for each TU group. Next, the base station may transmit a PDSCH(and/or DMRS) by using a TRP, panel and/or beam identical with a QCLreference RS configured and/or indicated for a corresponding TU group.Next, the pieces of configuration and/or indication information may betransmitted to the UE simultaneously or sequentially through differentmessages.

If the base station operates as described above, the UE may receive a TUgroup construction configuration and/or indication for multi-TU PDSCHtransmission to the base station and a corresponding multi-TU PDSCH.Next, the UE may receive (some of) QCL reference RS information to beapplied (to a specific QCL parameter set) for each TU group. Next, theUE may receive multi-TU PDSCH scheduling downlink control information(DCI). In this case, the UE may also receive (some of) the QCL referenceRS information to be applied (to a specific QCL parameter set) for eachTU group. Next, the UE may receive the PDSCH of a corresponding TUgroup, assuming that (a specific) QCL parameter(s) estimated and/orobtained from QCL reference RSs indicated and/or configured for each TUgroup of the multi-TU PDSCH is identical with a QCL parameter(s) (of aDMRS) of a PDSCH TU group mapped to the corresponding QCL reference RS.

The present disclosure can increase a communication success probabilitybecause link quality with another TRP, panel and/or beam is not greatlydeteriorated although link quality between a specific TRP, panel and/orbeam and a UE is deteriorated due to the blockage of a ray and/or abeam, UE rotation, UE mobility, etc. by (repeatedly) transmitting asignal (containing the same information) through different transmissionreception points (TRPs) or different panels and/or beams of the same TRPfor each TU group (or TU). In other words, the present disclosure canincrease a communication success probability through another TRP, paneland/or beam although link quality between a specific TRP, panel and/orbeam and a UE is deteriorated due to the blockage of a ray and/or abeam, UE rotation, UE mobility, etc. by (repeatedly) transmitting asignal (containing the same information) through different TRPs, ordifferent panels and/or beams of the same TRP for each TU group (or TU).

Hereinafter, the present disclosure proposes a method of configuring KQCL reference RSs for multiple TUs (or TU groups) (hereinafter a firstembodiment), a method of configuring QCL reference RSs for each layer ofa TU (hereinafter a second embodiment), and a method of mapping, to KQCL reference RSs, N TUs that configure a PDSCH (hereinafter a thirdembodiment).

Hereinafter, embodiments described in the present disclosure have beendivided for convenience of description, and some methods and/or someconfigurations, etc. of any embodiment may be substituted with a methodand/or configuration, etc. of another embodiment or they may be combinedand applied.

First Embodiment

First, a method of configuring K QCL reference RSs for multiple TUs (orTU groups) is described.

Hereinafter, the first embodiment is divided and described as a basestation operation and a UE operation, for convenience of description.

In particular, the first embodiment is divided and described as anoperating method of a base station for configuring K QCL reference RSsand an operating method of a UE if a base station operates as describedabove.

The following methods have been divided for convenience of description,and a configuration of any method may be substituted with aconfiguration of another method or the configurations may be combinedand applied.

First, an operation of a base station is specifically described.

The base station that has configured and/or indicated an N-TU PDSCH in aUE may divide N TUs into K TU groups according to the following proposedmethod(s) and may separately indicate and/or configure a QCL referenceRS(s) to be applied by the UE for each TU group.

(Method 1)—(Single TCI State for Multiple QCL References)

When a base station configures TCI state(s) (through RRC) in a UE, aspecific TCI state(s) may be configured as K(>1) QCL reference signals(RSs) with respect to the same QCL parameter(s). In the presentdisclosure, a “QCL reference RS” may mean a QCL RS or a QCL source.Furthermore, in the present disclosure, a “QCL reference RS” may besubstituted with a “TCI state.”

Next, if the base station allocates a multi-TU PDSCH (N>1) to thecorresponding UE and attempts to transmit a TRP, panel and/or beam whilechanging the TRP, panel and/or beam in a TU group unit, the base stationmay indicate and/or configure one of TCI state(s) having thecharacteristic based on downlink control information (DCI). In thepresent disclosure, a “multi-TU PDSCH” may mean PDSCHs transmitted andreceived in multiple TUs.

Next, the base station may divide, into K TU groups, N TUs thatconfigure a corresponding PDSCH previously configured in the UE orconfigured according to a method agreed based on a specific rule, andmay transmit (k=1, . . . , K) a PDSCH and PDSCH DMRS transmitted in ak-th TU group at a TRP, panel and/or beam that has transmitted a k-thQCL reference RS. In this case, a case where a k1-th QCL reference RSand a k2-th QCL reference RS (k1#k2) overlap may be permitted.

For example, when a QCL reference RS is the same for all ks, this mayindicate that this case corresponds to a case where one TRP, paneland/or beam transmits an N-TU PDSCH. For example, when a QCL referenceRS is the same for all ks, this may indicate that this case correspondsto a case where an N-TU PDSCH is transmitted in one TRP, panel and/orbeam.

(Method 2)—(multi-TCI state indication)

If a base station allocates a multi-TU PDSCH (N>1) to a corresponding UEand attempts to transmit a TRP, panel and/or beam while changing theTRP, panel and/or beam in a TU group unit, the base station mayseparately indicate and/or configure a TCI state indicative of a QCLreference RS to be applied for each TU group through radio resourcecontrol (RRC), a medium access control (MAC)-control element (CE) and/ordownlink control information (DCI).

For example, the base station may previously configure all K TCI statesthrough a higher layer message (e.g., RRC and/or MAC-CE), may omit TCIstate indication in multi-TU PDSCH scheduling DCI or may indicate agiven TCI state (not related to a TCI state that will participate inactual transmission) (Method 2-1).

And/or the base station may previously configure and/or indicate theremaining (K-D) TCI states other than a TCI state to be applied to aspecific TU group, among K TCI states, through a higher layer message,and may indicate (e.g., D=1) a TCI state to be applied to the specificTU group(s) through multi-TU PDSCH scheduling DCI (Method 2-2).

In Method 2-2, for more efficient signaling, a default TCI value (e.g.,a TCI value of a PDCCH that schedules a corresponding PDSCH, a TCI valueof the lowest CORESET or a default TCI value set by the base station) tobe used when TCI indication is omitted from scheduling DCI between theUE and the base station may be agreed, defined, regulated and/orconfigured. In this case, if a TRP, a panel and/or a beam correspondingto a default TCI attempts to transmit the PDSCH to the specific TUgroup, the TCI state indication may be omitted from the DCI. An exampleof the default TCI may include the TCI of a PDCCH that schedules thecorresponding PDSCH or a TCI state corresponding to the lowest CORESETID (of the latest TU) if a plurality of control resource sets (CORESETs)is configured. As an example of the specific TU group, a TU group thatis first transmitted or a TU group corresponding to the lowest TU groupindex, among a plurality of TU groups that configure the correspondingPDSCH, may be regulated.

And/or the base station may indicate all the K TCI states throughmulti-TU PDSCH scheduling DCI (Method 2-3). In the method, in order toreduce DCI overhead, some of the K TCI states may be regulated and/orconfigured to use a default TCI state. In this case, only the remainingTCI states except a TU group(s) that will apply a default TCI stateamong the K TCI states may be indicated through DCI.

For example, the base station may configure and/or transmit a list ofTCI states to the UE through RRC signaling. Next, the base station maygroup the TCI states included in the list through a MAC CE by K TCIstates with respect to the UE. In this case, the grouping number K maybe configured and/or determined as the number of TRPs participating inthe repetition of a PDSCH. Next, the base station may indicate, in theUE, the ID of a specific group of TCI state groups through DCI. The UEmay use K TCI states, included in a corresponding specific group, toreceive K TU groups (or TUs).

As a detailed example (K=2), the base station may configure and/ortransmit, to the UE, a list of TCI states {TCI state 00, TCI state 01,TCI state 02, TCI state 03, TCI state 04, TCI state 05 . . . }. Next,the base station may transmit, to the UE, grouping information(combination 00 {TCI state 00, TCI state 01}, combination 01 {TCI state02, TCI state 03}, combination 02 {TCI state 04, TCI state 05},combination 03 {TCI state 06, TCI state 07} . . . ). Next, the basestation may indicate the combination 03 in the UE through DCI. The UEmay receive a PDSCH from a first TRP by using the TCI state 06, and mayreceive a PDSCH from a second TRP by using the TCI state 07.

For example, the mapping of K TU groups (or TU) and K TCI states may beperformed by the method of the third embodiment. Through such a method,the present disclosure may indicate multiple TCI states through DCIhaving a small field size. In other words, the present disclosure canreduce a DCI size for indicating TCI states although a PDSCH istransmitted and received through multiple TRPs.

In order to reduce DCI overhead in the method, a (compact) TCI statelist to be used in the case of a multi-TU PDSCH separately from a TCIstate list generally used in the existing PDSCH, PDCCH and/or CSI-RS maybe configured through higher layer signaling. In this case, the payloadsize of DCI corresponding to each TCI state may be configured and/orregulated based on the size of the list.

In applying the method, a list of TCI state s to be used may beseparately configured depending on the number K of TCI states indicatedthrough DCI. For example, as K becomes great, a list configured with asmaller number of TCI states may be configured in order to reduce DCIpayload as much as possible by reducing the number of candidate TCIstates for each TU group (e.g., 64 TCI states for K=1 (6 bits)), 8 TCIstates for K=2 (3 bits), 4 TCI states for K=3 (2 bits)).

And/or the methods may be together (or mixed or merged) used. Forexample, a rule by which the method of Method 2-3 is used when K is aspecific value or less and to dynamically indicate TCI states throughDCI is abandoned and the method of Method 2-1 or Method 2-2 is used whenK is a specific value or more may be defined, agreed and/or configured.

Through the aforementioned methods, illustratively, a base station mayperform the following signal exchange and/or operation. First, the basestation may configure an N-TU PDSCH in a UE. Next, the base station maydivide N-slots into K TU groups. Next, the base station may determine aQCL reference RS (and/or determine a TRP, panel and/or beam that willtransmit a PDSCH for each TU group) for each TU group. Next, the basestation may indicate, in the UE, the QCL reference RS determined foreach TU group (transmitted in a TRP, a panel and/or a beam).

Accordingly, the present disclosure can increase a communication successprobability through another TRP, panel and/or beam although link qualitybetween a specific TRP, panel and/or beam and a UE is deteriorated dueto the blockage of a ray and/or a beam, UE rotation, UE mobility, etc.by (repeatedly) transmitting a signal (containing the same information)through different TRPs or panels and/or beams of the same TRP for eachTU group (or TU).

Hereinafter, in the present disclosure, a UE operation when the proposedmethods are applied is specifically described.

Each method and/or example in the base station operation may correspondto each method and/or example of the following UE operation.

A UE for which an N-TU PDSCH is configured and/or indicated may divide NTUs into K TU groups through the following proposed method(s), and mayconfigure a QCL reference RS(s) to be assumed for each TU group. In thepresent disclosure, an “N-TU PDSCH” may mean that a PDSCH is transmittedor received in N TUs.

(Method 1)—(Single TCI State for Multiple QCL References)

A UE may be configured with a TCI state list, including a TCI state(s)indicating K(>1) QCL reference RSs with respect to the same QCLparameter(s), from a base station (through a higher layer message).Next, the UE for which one of the TCI state(s) having the characteristichas been indicated through DCI that schedules a multi-TU PDSCH maydivide, into K TU groups, N TUs that configure the corresponding PDSCHaccording to a method previously configured (through a RRC message,etc.) or agreed according to a specific rule, and may assume that aPDSCH DMRS antenna port(s) (and the PDSCH REs of a corresponding TU)transmitted in a k-th TU group has been QCLed with a k-th QCL referenceRS and (with respect to a QCL parameter(s)) indicated in a TCI state(with respect to the same QCL parameter(s)) (k=1, K).

(Method 2)—(Multi-TCI State Indication)

A UE configured with a TCI state list and the reception of a multi-TUPDSCH (N>1) (through a higher layer message) may divide, into K TUgroups, N TUs that configure a corresponding PDSCH according to a methodpreviously configured (through a RRC message, etc.) or agreed accordingto a specific rule. The UE for which K TCI states for a correspondingPDSCH has been indicated through RRC, a MAC-CE and/or DCI may obtaininformation for a QCL reference RS to be applied to a K-th slot group,from the indicated K-th TCI state (k=1, K). In the method, the TCI statelist may have a characteristic including only one QCL reference RS withrespect to the same QCL parameter(s).

For example, the UE may be previously configured with all K TCI statesthrough a higher layer message (e.g., RRC and/or MAC-CE) (Method 2-1).In this case, the UE may expect that it will not receive TCI stateindication in DCI that schedules a multi-TU PDSCH. Alternatively, the UEmay neglect TCI state indication indicating DCI that schedules amulti-TU PDSCH. That is, the UE may neglect a TCI value indicatedthrough DCI, and may apply TCI states configured through a higher layermessage.

And/or the remaining (K-D) TCI states except a TCI state to be appliedto a specific TU group, among K TCI states, may be previously configuredand/or indicated for the UE through a higher layer message, and a TCIstate to be applied to a specific TU group(s) may be indicated for theUE through multi-TU PDSCH scheduling DCI (e.g., D=1) (Method 2-2).

In Method 2-2, for more efficient signaling, a default TCI value (e.g.,a TCI value of a PDCCH that schedules a corresponding PDSCH, a TCI valueof the lowest CORESET, or a default TCI value preset by a base station)to be used when TCI indication is omitted from scheduling DCI between aUE and the base station may be agreed and/or regulated. If the TCI stateindication is omitted from the DCI, a PDSCH (DMRS) received from aspecific TU group may be assumed to be QCLed with a QCL reference RScorresponding to a default TCI.

For example, the default TCI may be a TCI state corresponding to thelowest CORESET ID (of the latest TU) if a TCI of a PDCCH that schedulesa corresponding PDSCH or a plurality of CORESET is configured. Forexample, the specific TU group may be regulated as a TU group that isfirst transmitted or a TU group corresponding to the lowest TU groupindex, among a plurality of TU groups that configure the correspondingPDSCH.

And/or all K TCI states may be indicated for the UE through multi-TUPDSCH scheduling DCI (Method 2-3). In the method, some of the K TCIstates may be regulated and/or configured to use the default TCI stateproposed in Method 2-2. In this case, only the TCI states except a TUgroup(s) that will apply the default TCI state among the K TCI statesmay be indicated through DCI.

In the method, if a (compact) TCI state list to be used in the case of amulti-TU PDSCH separately from a TCI state list generally used in theexisting PDSCH, PDCCH and/or CSI-RS is configured through higher layersignaling, the payload size of DCI corresponding to each TCI state maybe configured and/or regulated based on the size of the list.

In applying the method, a TCI state list to be used based on the numberK of TCI states indicated through DCI may be separately configured. Forexample, it may be expected that as K increases, a list configured withthe same or smaller number of TCI states is configured in order toreduce DCI payload as much as possible by reducing the number ofcandidate TCI states for each TU group (e.g., 64 TCI states for K=1 64(6 bits), 8 TCI states for K=2 (3 bits), 4 TCI states for K=3 (2 bits))

And/or the methods may also be applied together (or mixed or merged).For example, it may be regulated that the method of Method 2-3 is usedwhen K is a specific value or less and to dynamically indicate TCIstates through DCI is abandoned and the method of Method 2-1 or Method2-2 is used when K is a specific value or more.

Through the aforementioned methods, illustratively, a UE may perform thefollowing signal exchange and/or operation.

The UE may obtain division information indicating that N-TUs are dividedinto K TU groups with respect to an N-TU PDSCH. Next, the UE may receiveN-TU PDSCH scheduling DCI. Next, the UE may obtain QCL reference RSinformation mapped to each TU group (with respect to a specific QCLparameter) (based on configured and/or indicated information). Next,when receiving a PDSCH (and DMRS) in each TU group, the UE may assumethat (a specific) QCL parameter(s) (e.g., Doppler, delay and a spatialRX parameter) estimated from the mapped QCL reference RS (antenna port)is identical with the corresponding PDSCH and a (specific) QCLparameter(s) of PDSCH DMRS antenna ports.

Accordingly, the present disclosure can increase a communication successprobability through another TRP, panel and/or beam although link qualitybetween a specific TRP, panel and/or beam and a UE is deteriorated dueto the blockage of a ray and/or a beam, UE rotation, UE mobility, etc.by (repeatedly) transmitting a signal (containing the same information)through different TRP, different panels and/or beams of the same TRP foreach TU group (or TU).

Second Embodiment

Next, a method of configuring a QCL reference RS for each layer of a TUis specifically described.

A method (so-called non-coherent joint transmission or independent layerjoint transmission) of separately configuring and/or designating a QCLreference RS for each layer group when transmitting and receiving aplurality of layers in a PDSCH transmitted and received in one TU mayalso be applied along with the proposed method of the first embodiment.

When the present disclosure is applied, a representative informationexchange and/or operation between a base station and a UE is as follows.

First, the base station may configure and/or indicate multi-TU PDSCHand/or DMRS group-based transmission in the UE. Furthermore, a DMRSgrouping information configuration and/or indication is possible.Furthermore, a TU grouping information configuration and/or indicationis possible.

Next, the base station may configure and/or indicate QCL reference RSinformation to be applied (to a specific QCL parameter set) for each TUgroup and/or each DMRS group (or layer group) in the UE. The basestation may transmit a PDSCH (and DMRS) by using a TRP, panel and/orbeam identical with a QCL reference RS configured and/or indicated withrespect to a corresponding DMRS group of a corresponding TU group. Theconfiguration and/or indication information may be transmitted to the UEsimultaneously or sequentially through different messages.

If the base station operates as described above, the UE may receive themulti-TU PDSCH and/or DMRS group-based transmission configuration and/orindication from the base station. Furthermore, DMRS grouping informationmay be configured and/or indicated for the UE. Furthermore, TU groupinginformation may be configured and/or indicated for the UE. Next, the UEmay receive (some of) QCL reference RS information to be applied (to aspecific QCL parameter set) for each TU group and each DMRS group.

Next, the UE may receive multi-TU PDSCH scheduling DCI from the basestation. In this case, the UE may also receive (some of) QCL referenceRS information to be applied (to a specific QCL parameter set) for eachTU group and each DMRS group.

Next, the UE may assume that a (specific) QCL parameter(s) estimatedand/or obtained from QCL reference RSs indicated and/or configured foreach DMRS group of each TU group of the multi-TU PDSCH from the basestation is identical with a QCL parameter(s) of the DMRS group of aPDSCH TU group mapped to the corresponding QCL reference RS, and mayreceive the PDSCH of the corresponding TU group.

The present disclosure can increase a communication success probabilitythrough link quality with another TRP, panel and/or beam although linkquality between a specific TRP, panel and/or beam and a UE isdeteriorated due to the blockage of a ray and/or a beam, UE rotation, UEmobility, etc. by transmitting a signal through different TRPs,different panels or different beams of the same TRP for each TU group(or TU), each DMRS group, each codeword (CW) and/or each TB.

In particular, the present disclosure can increase the probability thatwhen the same information is repeatedly transmitted for each TU, both aTB1 and a TB2 will be successfully received by a UE although a link witha specific TRP, panel and/or beam is deteriorated, by changing a TRP,panel and/or beam combination in which a TU group #1 transmits the TB1and the TB2 and a TRP, panel and/or beam combination in which a TU group#2 transmits the TB1 and the TB2.

For example, if two TU PDSCHs are indicated and rank 4 transmission isindicated, a QCL reference RS #0 for the 1^(st) and 2^(nd) layers of aPDSCH transmitted and/or received in a first TU, a QCL reference RS #1for the 3^(rd) and 4th layers of the PDSCH transmitted and/or receivedin the first TU, a QCL reference RS #3 for the 1^(st) and 2^(nd) layersof a PDSCH transmitted and/or received in a second TU, and a QCLreference RS #4 for the 3^(rd) and 4^(th) layers of the PDSCHtransmitted and/or received in the second TU may be separatelyconfigured and/or indicated. That is, if the first embodiment is amethod of indicating a k-th QCL reference RS for a k-th TU group, thesecond embodiment may be a method of extending and/or changing andapplying the first embodiment as a method of indicating a (k,n)-th QCLreference RS for an n-th layer group of the k-th TU group.

The following two cases may be assumed for N-TU PDSCH scheduling. One isa case where layer grouping is not changed for N TUs, and the other is acase where layer grouping can be changed in a TU or TU group unit.

If layer grouping is not changed for N TUs, the two methods may beconsidered assuming that M layer groups are maintained for N TUs.

For example, Method 1 of the first embodiment may be extended and/orchanged. In this case, when a base station configures K*M QCL referenceRSs for a specific TCI state(s) (with respect to the same QCLparameter(s)) and indicates a corresponding state through DCI, a UE maymap each QCL reference RS to an m-th layer group of a k-th TU group inan agreed sequence (e.g., first, a layer group and next a TU group orfirst a TU group and next a layer group), and may assume the QCLreference RS as a QCL source.

And/or Method 2 of the first embodiment may be extended and/or changed.In this case, when a base station configures and/or indicates K*MTCIstates for a specific N-TU PDSCH, a UE may map a QCL reference RS (for aspecific QCL parameter(s)), indicated in each TCI state, to an m-thlayer group of a k-th TU group in an agreed sequence (e.g., first, alayer group and next a TU group or first a TU group and next a layergroup), and may assume the QCL reference RS as a QCL source.

And/or if layer grouping can be changed in a TU or TU group unit,assuming that a total number of layer groups in a k-th TU group areM(k), the following methods may be considered.

For example, Method 1 of the first embodiment may be extended and/orchanged. In this case, when a base station configures Σ_(k=1) ^(K)M(k)QCL reference RSs for a specific TCI state(s) (with respect to the sameQCL parameter(s)) and then indicates a corresponding state through DCI,a UE may map each QCL reference RS to an m-th layer group of a k-th TUgroup in an agreed sequence (e.g., first, a layer group and next a TUgroup or first a TU group and next a layer group), and may assume theQCL reference RS as a QCL source.

And/or Method 2 of the first embodiment may be extended and/or changed.In this case, when a base station configures and/or indicates Σ_(k=1)^(K)M(k) TCI states for a specific N-TU PDSCH, a UE may map a QCLreference RS for (a specific QCL parameter(s)), indicated in each TCIstate, to an m-th layer group of a k-th TU group in an agreed sequence(e.g., first, a layer group and next a TU group or first a TU group andnext a layer group), and may assume the QCL reference RS as a QCLsource.

In the application of the methods, in order to reduce signalingoverhead, a rule by which only a specific set (or TCI states) of QCLreference RSs smaller than Σ_(k=1) ^(K)M(k) is indicated and/orconfigured and a corresponding QCL reference RS set is mapped to an m-thlayer group of a k-th TU group may be predetermined. If a plurality ofthe rules is regulated, a base station may configure and/or indicatewhich one of the plurality of rules will be applied. For example, it maybe assumed that only two QCL reference RS sets are configured and/orindicated. That is, it may be assumed that a QCL reference RS #0 and aQCL reference RS #1 are indicated and/or configured. Furthermore, it maybe assumed that a maximum of two layer groups are permitted. In thiscase, the following two rules for an N-TU PDSCH may be regulated. A basestation may indicate, for a UE, which method of the two rules will beapplied through RRC, a MAC-CE and/or DCI.

In a rule 1 (shuffle RSs over TUs), an RS #0 for the 1^(st) layer groupsof even-numbered TU groups, an RS #1 for the 2^(nd) layer groups of theeven-numbered TU groups, an RS #1 for the 1^(st) layer groups ofodd-numbered TU groups, and an RS #0 for the 2^(nd) layer groups of theodd-numbered TU groups may be mapped.

In a rule 2 (not shuffle RSs over TUs), an RS #0 for the 1^(st) layergroups of all TU groups and an RS #1 for the 2^(nd) layer groups of allthe TU groups may be mapped.

Furthermore, for example, it may be assumed that a total of three QCLreference RS #0, 1, 2 have been indicated and/or configured.Furthermore, it may be assumed that a maximum of two layer groups arepermitted. In this case, the following two rules are regulated for anN-TU PDSCH, and a base station may indicate, for a UE, which method ofthe two rules will be applied through RRC, a MAC-CE and/or DCI.Hereinafter, in RS #(i,j), i may mean a QCL reference RS to be appliedto the 1st layer group, and j may mean a QCL reference RS to be appliedto the 2nd layer group.

A rule1 (shuffle RSs over TUs): an RS #{0,1} for k-th TU groups, wherein(k mod 3)=0. An RS #{1,2} for the k-th TU groups, wherein (k mod 3)=1.An RS #{2,0} for the k-th TU groups, wherein (k mod 3)=2.

A rule2 (multi-TRP/beam+single TRP/beam): an RS #{0,1} for N1 TU groups,an RS #{2,2} for other N2 TU groups.

If the proposed method is applied, signaling overhead can be greatlyreduced because only a small number of RSs are indicated.

Third Embodiment

Next, a method of mapping N TUs that configure a PDSCH to K QCLreference RSs (for the same QCL parameter(s)) is specifically described.

Hereinafter, the proposed method may correspond to an operation ofdividing an N-TU into K TU groups (and/or an operation of configuringand/or indicating a QCL reference RS in each of the divided TU groupsthrough mapping information) in the illustrated base station operation.And/or hereinafter, the proposed method may correspond to an operationof obtaining division information for dividing an N-TU into K TU groupswith respect to an N-TU PDSCH (and/or an operation of obtaining QCLreference RS (mapping information) matched with each TU group) in the UEoperation.

In order to maximize reliability, it may be preferred to configure TUgroups in an equal number as much as possible based on a total number Nof TUs (aggregationFactorDL) forming a PDSCH and the number K of QCLreference RSs for the same QCL parameter(s). For example, assuming thatN□{2,4,8,16}, K□{1,2,3,4}, the number N_k of TUs included in a k-th TUgroup may be configured as follows. Values in the following table mean{N_1, . . . , N_K} in combinations of corresponding N values and Kvalues. That is, it may be more preferred to configure N_k values (k=1,. . . K) so that a deviation between the N_k values is small as much aspossible. Table 14 below illustrates an example in which the number ofTUs for each TU group is configured in an equal number.

TABLE 14 K = 1 K = 2 K = 3 K = 4 N = 2   {2} {1, 1} — — N = 4   {4} {2,2} {2, 1, 1} {1, 1, 1, 1} N = 8   {8} {4, 4} {3, 3, 2} {2, 2, 2, 2} N =16 {16} {8, 8} {6, 5, 5} {4, 4, 4, 4}

The present disclosure may be extended and used in addition to uses forincreasing reliability.

That is, the present disclosure may be used to transmit a different TBwithout repeatedly transmitting the same TB in each TU with respect to amulti-TU PDSCH.

In this case, different TRPs, panels and/or beams may transmit differentTBs to a UE for each TU group. When such a purpose is considered, theapplication of a combination having a great deviation may be consideredaccording to circumstances in addition to a combination having a smalldeviation between the N_k values (k=1, . . . K) as proposed above.Accordingly, a base station may configure and/or indicate a TU numberdistribution method (and a QCL reference RS mapping method for each TUon a corresponding distribution method) for the UE for each TU group tobe applied. That is, the base station may configure and/or indicate amethod of distributing the number of TUs for each TU group (and a QCLreference RS mapping method for each TU on a corresponding distributionmethod) for the UE.

Various methods may be present in performing TU grouping based on Table14. If synchronization between TRPs is well performed and cell coverageis small, there may be no need for muting between TUs as describedabove. In such a case, time diversity may be maximized by frequently andalternately transmitting a TRP, a panel and/or a beam as much aspossible. That is, a rule may be defined, agreed and/or configured sothat a TU group transmitted by one TRP is transmitted at a time intervalas wide as possible. An example of such a method is shown in Table 15.In Table 15, values may mean {K_1, . . . , K_N} in combinations ofcorresponding N values and K values. K_n may mean the index of a QCLreference RS to be applied in an n-th TU. K_n□{1, . . . ,K}. Theproposed method of Table 15 has a characteristic in which a QCLreference RS index is sequentially (or cyclically) mapped for each TUindex. The present method may be referred to as a “full shuffling method(or cyclic mapping method)”, for convenience sake.

TABLE 15 K = 1 K = 2 K = 3 K = 4 N = 2  {1, 1} {1, 2} — — N = 4  {1, 1,1, 1} {1, 2, 1, 2} {1, 2, 3, 1} {1, 2, 3, 4} N = 8  {1, 1, 1, 1, 1, 1,1, 1} {1, 2, 1, 2, 1, 2, 1, 2} {1, 2, 3, 1, 2, 3, 1, 2} {1, 2, 3, 4, 1,2, 3, 4} N = 16 {1, 1, 1, 1, 1, 1, 1, 1, {1, 2, 1, 2, 1, 2, 1, 2, {1, 2,3, 1, 2, 3, 1, 2, {1, 2, 3, 4, 1, 2, 3, 4, 1, 1, 1, 1, 1, 1, 1, 1} 1, 2,1, 2, 1, 2, 1, 2} 3, 1, 2, 3, 1, 2, 3, 1} 1, 2, 3, 4, 1, 2, 3, 4}

Meanwhile, if synchronization between TRPs is not well performed andcell coverage is great, muting between TUs may be necessary as describedabove. In such a case, if the method of Table 15 is applied, there is adisadvantage in that a muted symbol occurs in each boundary of all TUs.Furthermore, the method of Table 15 has a disadvantage in that animplementation is difficult if a close scheduling coordination betweenTRPs is difficult. In such a case, a proposed method of Table 16 may bemore preferred. A characteristic of the method of Table 16 is acharacteristic in which a QCL reference RS change number is minimized bymapping a k-th TU group to contiguous N_k TUs. The present method may bereferred to as a “sequential mapping method”, for convenience sake.

TABLE 16 K = 1 K = 2 K = 3 K = 4 N = 2  {1, 1} {1, 2} — — N = 4  {1, 1,1, 1} {1, 1, 2, 2} {1, 1, 2, 3} {1, 2, 3, 4} N = 8  {1, 1, 1, 1, 1, 1,1, 1} {1, 1, 1, 1, 2, 2, 2, 2} {1, 1, 1, 2, 2, 2, 3, 3} {1, 1, 2, 2, 3,3, 4, 4} N = 16 {1, 1, 1, 1, 1, 1, 1, 1, {1, 1, 1, 1, 1, 1, 1, 1, {1, 1,1, 1, 1, 1, 2, 2, {1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1} 2, 2,2, 2, 2, 2, 2, 2} 2, 2, 2, 3, 3, 3, 3, 3} 3, 3, 3, 3, 4, 4, 4, 4}

A mapping method having a form in which the advantages and disadvantagesof the methods of Tables 15 and 16 are mutually supplemented may also beconsidered. For example, when K=2 and N=8, the QCL reference RS changenumber may be made smaller than that in the method of Table 15 as in{1,1,2,2,1,1,2,2}, and time diversity may be obtained compared to themethod of Table 16. A characteristic of such a method is to configure ak-th TU group with a plurality of non-contiguous TU sub-groupsconfigured in contiguous TUs. The present method may be referred to as a“hybrid mapping method”, for convenience sake.

A base station may configure one of various TU group configurationmethods (or QCL reference RS mapping methods) for a UE (through a RRCmessage, etc.) as proposed above. And/or a TU group configuration methodsuitable for a specific use case may be regulated. For example, uponmulti-TU scheduling, the full shuffling method may be regulated to beused when a TB is repetitively transmitted (corresponding to a URLLC usecase), and the sequential mapping method may be regulated to be used ifa TB is not repetitively transmitted.

Likewise, a UE may be configured with one of various TU groupconfiguration methods (or QCL reference RS mapping methods) (through aRRC message, etc.) from a base station. Or a TU group configurationmethod suitable for a specific use case may be regulated for the UE.

FIG. 25 is a flowchart for describing an operating method of a UE, whichis proposed in the present disclosure.

Referring to FIG. 25, first, a UE (1000/2000 of FIGS. 27 to 30) mayreceive configuration information for configuring K time unit groups fora plurality of PDSCHs through different quasi co-location (QCL) sourcesignals (S2501). The QCL source signals may be signals transmitted bydifferent transmission points, panels or beams.

For example, the operation of receiving, by the UE, the configurationinformation in step S2501 may be implemented by apparatuses of FIGS. 27to 30 to be described hereinafter. For example, referring to FIG. 28,one or more processors 1020 may control one or more memories 1040 and/orone or more RF units 1060 in order to receive the configurationinformation. The one or more RF units 1060 may receive the configurationinformation.

Next, the UE (1000/2000 of FIGS. 27 to 30) may receive PDSCHconfiguration information including information for a plurality oftransmission configuration indication (TCI) states (S2502).

For example, the operation of receiving, by the UE, the PDSCHconfiguration information in step S2502 may be implemented by theapparatuses of FIGS. 27 to 30 to be described hereinafter. For example,referring to FIG. 28, the one or more processors 1020 may control theone or more memories 1040 and/or the one or more RF units 1060 in orderto receive the PDSCH configuration information. The one or more RF units1060 may receive the PDSCH configuration information.

Next, the UE (1000/2000 of FIGS. 27 to 30) may receive information for KTCI states corresponding to K time unit groups, among the plurality ofTCI states (S2503). For example, the operation of receiving theinformation for the K TCI states may be an operation of receiving amedia access control (MAC) control element (CE) including groupinginformation for the plurality of TCI states and receiving downlinkcontrol information (DCI) indicative of a specific group including the KTCI states. In this case, the DCI may schedule a plurality of PDSCHs intime units. The grouping information may be information that bundles theplurality of TCI states by K.

For example, the operation of receiving, by the UE, the information forthe K TCI states in step S2503 may be implemented by the apparatuses ofFIGS. 27 to 30 to be described hereinafter. For example, referring toFIG. 28, the one or more processors 1020 may control the one or morememories 1040 and/or the one or more RF units 1060 in order to receivethe information for the K TCI states. The one or more RF units 1060 mayreceive the information for the K TCI states.

Next, the UE (1000/2000 of FIGS. 27 to 30) may receive a plurality ofPDSCHs based on the K TCI states (S2504). The K TCI states may be usedto receive PDSCHs in corresponding time unit groups, respectively.

The TCI state may include information for a quasi co-location (QCL)reference signal and information for a QCL type.

An antenna port of a PDSCH demodulation reference signal of each of thetime unit groups may be assumed to have a QCL relation with an antennaport of a QCL reference signal mapped to each of the time unit groups.

The time unit group includes multiple time units. The time unit mayinclude at least one of one or more slots and/or one or more symbols.

The PDSCHs may be received from different transmission points (1000/2000of FIGS. 27 to 30), panels (1000/2000 of FIGS. 27 to 30), or beams(1000/2000 of FIGS. 27 to 30) for each time unit group.

For example, the operation of receiving, by the UE, the plurality ofPDSCHs in step S2504 may be implemented by the apparatuses of FIGS. 27to 30 to be described hereinafter. For example, referring to FIG. 28,the one or more processors 1020 may control the one or more memories1040 and/or the one or more RF units 1060 in order to receive theplurality of PDSCHs. The one or more RF units 1060 may receive theplurality of PDSCHs.

The operations of the UE described with reference to FIG. 25 are thesame as the operations (e.g., the first embodiment to the thirdembodiment) of the UE described with reference to FIGS. 1 to 24, andthus other detailed description is omitted.

The aforementioned signaling and operation may be implemented by theapparatuses (e.g., FIGS. 27 to 30) to be described hereafter. Forexample, the aforementioned signaling and operation may be processed bythe one or more processors 1010, 2020 of FIGS. 27 to 3. Theaforementioned signaling and operation may be stored in a memory (e.g.,1040, 2040) in the form of an instruction/program (e.g., instruction,executable code) for driving at least one processor (e.g., 1010, 2020)of FIGS. 27 to 30.

FIG. 26 is a flowchart for describing an operating method of a basestation, which is proposed in the present disclosure.

Referring to FIG. 26, first, a base station (1000/2000 of FIGS. 27 to30) may transmit, to a UE, configuration information for configuring Ktime unit groups for the transmission of a plurality of PDSCHs throughdifferent quasi co-location (QCL) source signals (S2601). The QCL sourcesignals may be signals transmitted by different transmission points,panels, or beams.

For example, the operation of transmitting, by the base station, theconfiguration information to the UE in step S2601 may be implemented bythe apparatuses of FIGS. 27 to 30 to be described hereinafter. Forexample, referring to FIG. 28, the one or more processors 1020 maycontrol the one or more memories 1040 and/or the one or more RF units1060 in order to transmit the configuration information. The one or moreRF units 1060 may transmit the configuration information to the UE.

Next, the base station (1000/2000 of FIGS. 27 to 30) may transmit, tothe UE, PDSCH configuration information including information for aplurality of transmission configuration indication (TCI) states (S2602).

For example, the operation of transmitting, by the base station, thePDSCH configuration information to the UE in step S2602 may beimplemented by the apparatuses of FIGS. 27 to 30 to be describedhereinafter. For example, referring to FIG. 28, the one or moreprocessors 1020 may control the one or more memories 1040 and/or the oneor more RF units 1060 in order to transmit the PDSCH configurationinformation. The one or more RF units 1060 may transmit the PDSCHconfiguration information to the UE.

Next, the base station (1000/2000 of FIGS. 27 to 30) may transmit, tothe UE, information for K TCI states corresponding to K time unitgroups, among the plurality of TCI states (S2603). For example, theoperation of transmitting the information for the K TCI states to the UEmay be an operation of transmitting, to the UE, a media access control(MAC) control element (CE) including grouping information for theplurality of TCI states and transmitting, to the UE, downlink controlinformation (DCI) indicative of a specific group including the K TCIstates. In this case, the DCI may schedule a plurality of PDSCHs in timeunits.

For example, the operation of transmitting, by the base station, theinformation for the K TCI states to the UE in step S2603 may beimplemented by the apparatuses of FIGS. 27 to 30 to be describedhereinafter. For example, referring to FIG. 28, the one or moreprocessors 1020 may control the one or more memories 1040 and/or the oneor more RF units 1060 in order to transmit the information for the K TCIstates. The one or more RF units 1060 may transmit the information forthe K TCI states to the UE.

Next, the base station (1000/2000 of FIGS. 27 to 30) may transmit aplurality of PDSCHs to the UE based on the K TCI states (S2604). The KTCI states may be used to receive PDSCHs in corresponding time unitgroups, respectively.

The TCI state may include information for a quasi co-location (QCL)reference signal and information for a QCL type.

An antenna port of a PDSCH demodulation reference signal of each of thetime unit groups may be assumed to have a QCL relation with an antennaport of a QCL reference signal mapped to each of the time unit groups.

The time unit group includes multiple time units. The time unit mayinclude at least one of one or more slots and/or one or more symbols.

The PDSCHs may be received from different transmission points (1000/2000of FIGS. 27 to 30), panels (1000/2000 of FIGS. 27 to 30), or beams(1000/2000 of FIGS. 27 to 30) for each time unit group.

For example, the operation of transmitting, by the base station, theplurality of PDSCHs to the UE in step S2604 may be implemented by theapparatuses of FIGS. 27 to 30 to be described hereinafter. For example,referring to FIG. 28, the one or more processors 1020 may control theone or more memories 1040 and/or the one or more RF units 1060 in orderto transmit the plurality of PDSCHs. The one or more RF units 1060 maytransmit the plurality of PDSCHs to the UE.

The operations of the base station described with reference to FIG. 26are the same as the operations (e.g., the first embodiment to the thirdembodiment) of the base station described with reference to FIGS. 1 to25, and thus other detailed description is omitted.

The aforementioned signaling and operation may be implemented by theapparatuses (e.g., FIGS. 27 to 30) to be described hereafter. Forexample, the aforementioned signaling and operation may be processed bythe one or more processors 1010, 2020 of FIGS. 27 to 30. Theaforementioned signaling and operation may be stored in a memory (e.g.,1040, 2040) in the form of an instruction/program (e.g., instruction,executable code) for driving at least one processor (e.g., 1010, 2020)of FIGS. 27 to 30.

Example of a Communication System to which the Present Disclosure isApplied

The present disclosure is not limited thereto, and the variousdescriptions, functions, procedures, proposals, methods and/or operatingflowcharts disclosed in the present disclosure may also be applied tovarious fields which require wireless communication/connection (e.g.,5G) between devices.

Hereinafter, the present disclosure is more specifically illustratedwith reference to drawings. In following drawings/descriptions, areference numeral may illustrate a corresponding hardware block,software block or function block unless the same reference numeral isdescribed otherwise.

FIG. 27 illustrates a communication system 10 to which the presentdisclosure is applied.

Referring to FIG. 27, the communication system 10 to which the presentdisclosure is applied includes a wireless device, a base station and anetwork. In this case, the wireless device means a device performingcommunication by using radio access technologies (e.g., 5G new RAT (NR))or long term evolution (LTE)), and may be denoted as acommunication/wireless/5G device. The present disclosure is not limitedthereto, and the wireless device may include a robot 100 a, vehicles1000 b-1 and 1000 b-2, an extended reality (XR) device 1000 c, ahandheld device 1000 d, home appliances 1000 e, an Internet of Thing(IoT) device 1000 f, and an AI device/server 4000. For example, thevehicle may include a vehicle having a wireless communication function,an autonomous vehicle, a vehicle capable of performing communicationbetween vehicles, etc. In this case, the vehicle may include an unmannedaerial vehicle (UAV) (e.g., drone). The XR device includes an augmentedreality (AR)/virtual reality (VR)/mixed reality (MR) device, and may beimplemented in the form of a head-mounted device (HMD), a head-updisplay (HUD) included in a vehicle, television, a smartphone, acomputer, a wearable device, a home appliance device, digital signage, avehicle, a robot, etc. The handheld device may include a smartphone, asmart pad, a wearable device (e.g., a smart watch and smart glasses), acomputer (e.g., a notebook), etc. The home appliances may include TV, arefrigerator, a washing machine, etc. The IoT device may include asensor, a smart meter, etc. For example, the base station or the networkmay be implemented as a wireless device. A specific wireless device 2000a may operate as a base station/network node with respect to anotherwireless device.

The wireless devices 1000 a to 1000 f may be connected to a network 3000through a base station 2000. An artificial intelligence (AI) technologymay also be applied to the wireless devices 1000 a to 1000 f. Thewireless devices 1000 a to 1000 f may be connected to the AI server 4000over the network 300. The network 3000 may be configured using a 3Gnetwork, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. Thewireless devices 1000 a to 1000 f may communicate with each otherthrough the base station 2000/network 3000, but may directly communicatewith each other (e.g. sidelink communication) without the interventionof the base station/network. For example, the vehicles 1000 b-1 and 1000b-2 may directly communicate with each other (e.g. vehicle to vehicle(V2V)/vehicle to everything (V2X) communication). Furthermore, the IoTdevice (e.g., a sensor) may directly communicate with another IoT device(e.g., a sensor) or other wireless devices 1000 a to 1000 f.

Wireless communication/connection 1500 a, 1500 b, and 1500 c may beperformed between the wireless devices 1000 a to 1000 f/base station2000, the base station 2000/base station 2000. In this case, thewireless communication/connection may be performed through various radioaccess technologies (e.g., 5G NR), such as uplink/downlink communication1500 a and sidelink communication 1500 b (or D2D communication), andcommunication 1500 c between base stations (e.g. relay, integratedaccess backhaul (IAB). The wireless device and the base station/wirelessdevice, the base station and the base station may transmit/receive radiosignals to one another through the wireless communication/connection1500 a, 1500 b, or 1500 c. For example, signals may be maytransmitted/received using the wireless communication/connection 1500 a,1500 b, or 1500 c through various physical channels. To this end, atleast some of various configuration information configuration processesfor the transmission/reception of a radio signal, various signalprocessing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), a resourceallocation process, etc. may be performed based on various proposals ofthe present disclosure.

Example of a Wireless Device to which the Present Disclosure is Applied

FIG. 28 illustrates a wireless device to which the present disclosuremay be applied.

Referring to FIG. 28, the first wireless device 1000 and the secondwireless device 2000 may transmit and receive radio signals by usingvarious radio access technologies (e.g., LTE, NR). In this case, {thefirst wireless device 1000, the second wireless device 2000} maycorrespond to {wireless device 1000 x, base station 2000} and/or{wireless device 1000 x, wireless device 1000 x} of FIG. 27.

The first wireless device 1000 includes the one or more processors 1020and the one or more memories 1040, and may further include the one ormore transceivers 1060 and/or the one or more antennas 1080. Theprocessor 1020 may be configured to control the memory 1040 and/or thetransceiver 1060 and to implement the description, function, procedure,proposal, method and/or operating flowchart disclosed in the presentdisclosure. For example, the processor 1020 may generate a firstinformation/signal by processing information within the memory 1040, andmay then transmit a radio signal including the first information/signalthrough the transceiver 1060. Furthermore, the processor 1020 mayreceive a radio signal including a second information/signal through thetransceiver 1060, and may then store, in the memory 1040, informationobtained by the signal processing of the second information/signal. Thememory 1040 may be connected to the processor 1020, and may storevarious types of information related to an operation of the processor1020. For example, the memory 1040 may store a software code, includinginstructions for performing some or all of processes controlled by theprocessor 1020 or performing the description, function, procedure,proposal, method and/or operating flowchart disclosed in the presentdisclosure. In this case, the processor 1020 and the memory 1040 may bea part of a communication modem/circuit/chip designed to implement awireless communication technology (e.g., LTE or NR). The transceiver1060 may be connected to the processor 1020, and may transmit and/orreceive a radio signal through the one or more antennas 1080. Thetransceiver 1060 may include a transmitter and/or a receiver. Thetransceiver 1060 may be interchangeably used with a radio frequency (RF)unit. In the present disclosure, the wireless device may mean acommunication modem/circuit/chip.

The second wireless device 2000 includes one or more processors 2020 andone or more memories 2040, and may further include one or moretransceivers 2060 and/or one or more antennas 2080. The processor 2020may be configured to control the memory 2040 and/or the transceiver 2060and to implement the description, function, procedure, proposal, methodand/or operating flowchart disclosed in the present disclosure. Forexample, the processor 2020 may generate a third information/signal byprocessing information within the memory 2040, and may then transmit aradio signal including the third information/signal through thetransceiver 2060. Furthermore, the processor 2020 may receive a radiosignal including a fourth information/signal through the transceiver2060, and may then store, in the memory 2040, information obtained bythe signal processing of the fourth information/signal. The memory 2040may be connected to the processor 2020, and may store various types ofinformation related to an operation of the processor 2020. For example,the memory 2040 may store a software code, including instructions forperforming some or all of processes controlled by the processor 2020 orperforming the description, function, procedure, proposal, method and/oroperating flowchart disclosed in the present disclosure. In this case,the processor 2020 and the memory 2040 may be a part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE or NR). The transceiver 2060 may be connected tothe processor 2020, and may transmit and/or receive a radio signalthrough the one or more antennas 2080. The transceiver 2060 may includea transmitter and/or a receiver. The transceiver 2060 may beinterchangeably used with an RF unit. In the present disclosure, thewireless device may mean a communication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 1000 and 2000 aremore specifically described. The present disclosure is not limitedthereto, and one or more protocol layers may be implemented by the oneor more processors 1020, 2020. For example, the one or more processors1020, 2020 may implement one or more layers (e.g., functional layerssuch as PHY, MAC, RLC, PDCP, RRC, and SDAP). The one or more processors1020, 2020 may generate one or more protocol data units (PDUs) and/orone or more service data units (SDUs) according to the description,function, procedure, proposal, method and/or operating flowchartdisclosed in the present disclosure. The one or more processors 1020,2020 may generate a message, control information, data or informationaccording to the description, function, procedure, proposal, methodand/or operating flowchart disclosed in the present disclosure. The oneor more processors 1020, 2020 may generate a signal (e.g., a basebandsignal), including a PDU, an SDU, a message, control information, dataor information, according to the function, procedure, proposal and/ormethod disclosed in the present disclosure, and may provide the signalto the one or more transceivers 1060, 2060. The one or more processors1020, 2020 may receive a signal (e.g., a baseband signal) from the oneor more transceivers 1060, 2060, and may obtain a PDU, an SDU, amessage, control information, data or information according to thedescription, function, procedure, proposal, method and/or operatingflowchart disclosed in the present disclosure.

The one or more processors 1020, 2020 may be denoted as a controller, amicro controller, a micro processor or a micro computer. The one or moreprocessors 1020, 2020 may be implemented by hardware, firmware,software, or a combination of them. For example, one or moreapplication-specific integrated circuits (ASICs), one or more digitalsignal processors (DSPs), one or more digital signal processing devices(DSPDs), one or more programmable logic devices (PLDs) or one or morefield programmable gate arrays (FPGAs) may be included in the one ormore processors 1020, 2020. The description, function, procedure,proposal, method and/or operating flowchart disclosed in the presentdisclosure may be implemented using firmware or software. The firmwareor the software may be implemented to include a module, a procedure, afunction, etc. The firmware or software configured to perform thedescription, function, procedure, proposal, method and/or operatingflowchart disclosed in the present disclosure may be included in the oneor more processors 1020, 2020 or may be stored in the one or morememories 1040, 2050 and driven by the one or more processors 1020, 2020.The description, function, procedure, proposal, method and/or operatingflowchart disclosed in the present disclosure may be implemented usingfirmware or software in the form of a code, an instruction and/or a setof instructions.

The one or more memories 1040, 2050 may be connected to the one or moreprocessors 1020, 2020, and may store various forms of data, signals,messages, information, programs, codes, indication and/or instructions.The one or more memories 1040, 2050 may be configured as a ROM, a RAM,an EPROM, a flash memory, a hard drive, a register, a cache memory, acomputer-readable storage medium and/or a combination of them. The oneor more memories 1040, 2050 may be positioned inside and/or outside theone or more processors 1020, 2020. Furthermore, the one or more memories1040, 2050 may be connected to the one or more processors 1020, 2020 byusing various technologies, such as a wired or wireless connection.

The one or more transceivers 1060, 2060 may transmit, to one or moreother devices, user data, control information, a radio signal/channel,etc. described in the methods and/or the operating flowcharts of thepresent disclosure. The one or more transceivers 1060, 2060 may receive,from the one or more other devices, user data, control information, aradio signal/channel, etc. described in the description, the function,the procedure, the proposal, the method and/or the operating flowchartdisclosed in the present disclosure. For example, the one or moretransceivers 1060, 2060 may be connected to the one or more processors1020, 2020, and may transmit and receive radio signals. For example, theone or more processors 1020, 2020 may control the one or moretransceivers 1060, 2060 to transmit user data, control information or aradio signal to one or more other devices. Furthermore, the one or moreprocessors 1020, 2020 may control the one or more transceivers 1060,2060 to receive user data, control information or a radio signal fromthe one or more other devices. Furthermore, the one or more transceivers1060, 2060 may be connected to the one or more antennas 1080, 2080. Theone or more transceivers 1060, 2060 may be configured to transmit andreceive user data, control information, a radio signal/channel, etc.,described in the description, the function, the procedure, the proposal,the method and/or the operating flowchart disclosed in the presentdisclosure, through the one or more antennas 1080, 2080. In the presentdisclosure, the one or more antennas may be a plurality of physicalantennas or a plurality of logical antennas (e.g., antenna ports). Theone or more transceivers 1060, 2060 may convert a received radiosignal/channel from an RF band signal to a baseband signal in order toprocess received user data, control information, a radio signal/channel,etc. by using the one or more processors 1020, 2020. The one or moretransceivers 1060, 2060 may convert the user data, control information,radio signal/channel, etc., processed using the one or more processors1020, 2020, from a baseband signal to an RF band signal. To this end,the one or more transceivers 1060, 2060 may include an (analog)oscillator and/or a filter.

Example of a Wireless Device to which the Present Disclosure is Applied

FIG. 29 illustrates another example of a wireless device to which thepresent disclosure is applied.

The wireless device may be implemented in various forms depending on ause-example/service (refer to FIG. 27). Referring to FIG. 29, thewireless device 1000, 2000 corresponds to the wireless device 1000, 2000of FIG. 28, and may be configured as various elements, components,parts/units and/or modules. For example, the wireless device 1000, 2000may include a communication unit 1100, a control unit 1200, a memoryunit 1300 and additional components 1400. The communication unit mayinclude a communication circuit 1120 and a transceiver(s) 1140. Forexample, the communication circuit 1120 may include the one or moreprocessors 1020, 2020 and/or the one or more memories 1040, 2040 of FIG.28. For example, the transceiver(s) 1140 may include the one or moretransceivers 1060, 2060 and/or the one or more antennas 1080, 2080 ofFIG. 28. The control unit 1200 is electrically connected to thecommunication unit 1100, the memory unit 1300 and the additionalcomponents 1400, and controls an overall operation of the wirelessdevice. For example, the control unit 1200 may control anelectrical/mechanical operation of the wireless device based on aprogram/code/instruction/information stored in the memory unit 1300.Furthermore, the control unit 1200 may transmit, through awireless/wired interface, information stored in the memory unit 1300 tothe outside (e.g., another communication device) through thecommunication unit 1100, or may store, in the memory unit 1300,information through a wireless/wired interface from the outside (e.g.,another communication device) through the communication unit 1100.

The additional components 1400 may be variously configured depending onthe type of wireless device. For example, the additional components 1400may include at least one of a power unit/battery, an input/output (I/O)unit, a driving unit and a computing unit. The present disclosure is notlimited thereto, and the wireless device may be implemented in the formof the robot (1000 a in FIG. 27), the vehicle (1000 b-1, 1000 b-2 inFIG. 27), the XR device (1000 c in FIG. 27), the handheld device (1000 din FIG. 27), the home appliances (1000 e in FIG. 27), the IoT device(1000 f in FIG. 27), a terminal for digital broadcasting, a hologramdevice, a public safety device, an MTC device, a medical device, aFintech device (or financial device), a security device, aweather/environment device, the AI server/device (4000 in FIG. 27), thebase station (2000 in FIG. 27), a network node, etc. The wireless devicemay be movable or used at a fixed place depending on ause-example/service.

In FIG. 29, all of the various elements, components, parts/units and/ormodules within the wireless device 1000, 2000 may be interconnectedthrough a wired interface or at least some thereof may be wirelesslyconnected through the communication unit 1100. For example, the controlunit 1200 and the communication unit 1100 may be connected through wireswithin the wireless device 1000, 2000. The control unit 1200 and a firstunit (e.g., 1300, 1400) may be wirelessly connected through thecommunication unit 1100. Furthermore, each of the elements, components,parts/units and/or modules within the wireless device 1000, 2000 mayfurther include one or more components. For example, the control unit1200 may be configured as a set of one or more processors. For example,the control unit 1200 may be configured as a set, such as communicationcontrol processors, application processors, electronic processors(ECUs), graphic processing processors, or memory control processors.Furthermore, for example, the memory unit 1300 may be configured as arandom access memory (RAM), a dynamic RAM (DRAM), a read only memory(ROM), a flash memory, a volatile memory, a non-volatile memory and/or acombination of them.

FIG. 30 illustrates a handheld device to which the present disclosure isapplied.

The handheld device may include a smartphone, a smart pad, a wearabledevice (e.g., a smart watch or a smart glasses), and a portable computer(e.g., a notebook). The handheld device may be denoted as a mobilestation (MS), a user terminal (UT), a mobile subscriber station (MSS), asubscriber station (SS), an advanced mobile station (AMS) or a wirelessterminal (WT).

Referring to FIG. 30, the handheld device 1000 may include an antennaunit 1080, a communication unit 1100, a control unit 1200, a memory unit1300, a power supply unit 1400 a, an interface unit 1400 b, and aninput/output (I/O) unit 1400 c. The antenna unit 1080 may be configuredas a part of the communication unit 1100. The blocks 1100 to 1300/1400 ato 1400 c correspond to the blocks 1100 to 1300/1400 of FIG. 29,respectively.

The communication unit 1100 may transmit and receive signals (e.g., dataor control signals) to and from other wireless devices or base stations.The control unit 1200 may perform various operations by controllingcomponents of the handheld device 1000. The control unit 1200 mayinclude an application processor (AP). The memory unit 1300 may storedata/parameters/programs/codes/instructions necessary for the driving ofthe handheld device 1000. Furthermore, the memory unit 1300 may storeinput/output data/information, etc. The power supply unit 1400 asupplies power to the handheld device 1000, and may include awired/wireless charging circuit, a battery, etc. The interface unit 1400b may support a connection between the handheld device 1000 and anotherexternal device. The interface unit 1400 b may include various ports(e.g., an audio input/output port and a video input/output port) for aconnection with an external device. The input/output unit 1400 c mayreceive or output image information/signal, audio information/signal,data and/or information by a user. The input/output unit 1400 c mayinclude a camera, a microphone, a user input unit, a display 1400 d, aspeaker and/or a haptic module.

For example, in the case of data communication, the input/output unit1400 c may obtain information/signal (e.g., a touch, text, a voice, animage, or video) input by a user. The obtained information/signal may bestored in the memory unit 1300. The communication unit 1100 may convert,into a radio signal, information/signal stored in the memory, and maydirectly transmit the converted radio signal to another wireless deviceor may transmit the converted radio signal to a base station.Furthermore, after receiving a radio signal from another wireless deviceor the base station, the communication unit 1100 may restore thereceived radio signal to the original information/signal. The restoredinformation/signal may be stored in the memory unit 1300 and output invarious forms (e.g., text, a voice, an image, video, and haptic) throughthe input/output unit 1400 c.

In the aforementioned embodiments, the components and characteristics ofthe present disclosure have been combined in a specific form. Each ofthe components or characteristics may be considered to be optionalunless otherwise described explicitly. Each of the components orcharacteristics may be implemented in a form to be not combined withother components or characteristics. Furthermore, some of the componentsor the characteristics may be combined to form an embodiment of thepresent disclosure. The sequence of the operations described in theembodiments of the present disclosure may be changed. Some of thecomponents or characteristics of an embodiment may be included inanother embodiment or may be replaced with corresponding components orcharacteristics of another embodiment. It is evident that an embodimentmay be constructed by combining claims not having an explicit citationrelation in the claims or may be included as a new claim by amendmentsafter filing an application.

The embodiment according to the present disclosure may be implemented byvarious means, for example, hardware, firmware, software or acombination of them. In the case of an implementation by hardware, theembodiment of the present disclosure may be implemented using one ormore application-specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, microcontrollers, microprocessors,etc.

In the case of an implementation by firmware or software, the embodimentof the present disclosure may be implemented in the form of a module,procedure or function for performing the aforementioned functions oroperations. Software code may be stored in the memory and driven by theprocessor. The memory may be located inside or outside the processor andmay exchange data with the processor through a variety of known means.

It is evident to those skilled in the art that the present disclosuremay be materialized in other specific forms without departing from theessential characteristics of the present disclosure. Accordingly, thedetailed description should not be construed as being limitative fromall aspects, but should be construed as being illustrative. The scope ofthe present disclosure should be determined by reasonable analysis ofthe attached claims, and all changes within the equivalent range of thepresent disclosure are included in the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

In the wireless communication system of the present disclosure, thescheme for transmitting and receiving PDSCHs has been described based onan example in which the scheme is applied to a 3GPP LTE/LTE-A system anda 5G system (new RAT system), but may also be applied to variouswireless communication systems in addition to the 3GPP LTE/LTE-A systemand the 5G system (new RAT system).

1. A method of receiving, by a user equipment (UE), a plurality ofphysical downlink shared channels (PDSCHs) in a wireless communicationsystem, the method comprising: receiving configuration information forconfiguring K time unit groups to receive the plurality of PDSCHsthrough different quasi co-location (QCL) source signals; receivingPDSCH configuration information including information for a plurality oftransmission configuration indication (TCI) states; receivinginformation for K TCI states corresponding to the K time unit groupsamong the plurality of TCI states; and receiving the plurality of PDSCHsbased on the K TCI states.
 2. The method of claim 1, wherein receivingthe information for the K TCI states includes: receiving a media accesscontrol (MAC) control element (CE) including grouping information forthe plurality of TCI states; and receiving downlink control information(DCI) indicating a specific group including the K TCI states.
 3. Themethod of claim 2, wherein the DCI schedules a plurality of PDSCHs inthe time units.
 4. The method of claim 1, wherein the K TCI states areused to receive the PDSCHs in corresponding time unit groups,respectively.
 5. The method of claim 1, wherein the TCI state includesinformation for a QCL reference signal and information for a QCL type.6. The method of claim 5, wherein an antenna port of a PDSCHdemodulation reference signal of each of the time unit groups is assumedto have a QCL relation with an antenna port of a QCL reference signalmapped to each of the time unit groups.
 7. The method of claim 1,wherein the time unit group includes multiple time units, and whereinthe time unit includes at least one of one or more slots and/or one ormore symbols.
 8. The method of claim 1, wherein the PDSCH is receivedfrom a different transmission point, panel, or beam for each time unitgroup.
 9. A user equipment (UE) receiving a plurality of physicaldownlink shared channels (PDSCHs) in a wireless communication system,comprising: a transceiver for transmitting and receiving radio signals,and a processor functionally coupled to the transceiver, wherein theprocessor is configured to control to: receive configuration informationfor configuring K time unit groups to receive the plurality of PDSCHsthrough different quasi co-location (QCL) source signals, receive PDSCHconfiguration information including information for a plurality oftransmission configuration indication (TCI) states, receive informationfor K TCI states corresponding to the K time unit groups among theplurality of TCI states, and receive the plurality of PDSCHs based onthe K TCI states.
 10. A base station (BS) transmitting a plurality ofphysical downlink shared channels (PDSCHs) in a wireless communicationsystem, comprising: a transceiver for transmitting and receiving radiosignals, and a processor functionally coupled to the transceiver,wherein the processor is configured to control to: transmit, to a userequipment (UE), configuration information for configuring K time unitgroups to transmit the plurality of PDSCHs through different quasico-location (QCL) source signals, transmit, to the UE, PDSCHconfiguration information including information for a plurality oftransmission configuration indication (TCI) states, transmit, to the UE,information for K TCI states corresponding to the K time unit groupsamong the plurality of TCI states, and transmit the plurality of PDSCHsto the UE based on the K TCI states.
 11. The BS of claim 10, wherein theprocessor is configured to: transmit, to the UE, a media access control(MAC) control element (CE) including grouping information for theplurality of TCI states; and transmit, to the UE, downlink controlinformation (DCI) indicating a specific group including the K TCIstates.
 12. The BS of claim 10, wherein the K TCI states are used toreceive the PDSCHs in corresponding time unit groups, respectively. 13.The BS of claim 10, wherein the TCI state includes information for a QCLreference signal and information for a QCL type.
 14. The BS of claim 13,wherein an antenna port of a PDSCH demodulation reference signal of eachof the time unit groups is assumed to have a QCL relation with anantenna port of a QCL reference signal mapped to each of the time unitgroups.
 15. The BS of claim 10, wherein the time unit group includesmultiple time units, and wherein the time unit includes at least one ofone or more slots and/or one or more symbols.